
#ifdef ZIP_STD
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <memory.h>
#include <string.h>
#include <ctype.h>

#include "zip.h"
//
typedef unsigned short WORD;
#define _tcslen strlen
#define _tcsicmp stricmp
#define _tcsncpy strncpy
#define _tcsstr strstr
#define INVALID_HANDLE_VALUE 0
#ifndef _T
#define _T(s) s
#endif
#ifndef S_IWUSR
#define S_IWUSR 0000200
#define S_ISDIR(m) (((m) & _S_IFMT) == _S_IFDIR)
#define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
#endif

//
#else

#include <windows.h>
#include <tchar.h>
#include <ctype.h>
#include <stdio.h>
#include "zip.h"
#endif


// THIS FILE is almost entirely based upon code by info-zip.
// It has been modified by Lucian Wischik. The modifications
// were a complete rewrite of the bit of code that generates the
// layout of the zipfile, and support for zipping to/from memory
// or handles or pipes or pagefile or diskfiles, encryption, unicode.
// The original code may be found at http://www.info-zip.org
// The original copyright text follows.
//
//
//
// This is version 1999-Oct-05 of the Info-ZIP copyright and license.
// The definitive version of this document should be available at
// ftp://ftp.cdrom.com/pub/infozip/license.html indefinitely.
//
// Copyright (c) 1990-1999 Info-ZIP.  All rights reserved.
//
// For the purposes of this copyright and license, "Info-ZIP" is defined as
// the following set of individuals:
//
//   Mark Adler, John Bush, Karl Davis, Harald Denker, Jean-Michel Dubois,
//   Jean-loup Gailly, Hunter Goatley, Ian Gorman, Chris Herborth, Dirk Haase,
//   Greg Hartwig, Robert Heath, Jonathan Hudson, Paul Kienitz, David Kirschbaum,
//   Johnny Lee, Onno van der Linden, Igor Mandrichenko, Steve P. Miller,
//   Sergio Monesi, Keith Owens, George Petrov, Greg Roelofs, Kai Uwe Rommel,
//   Steve Salisbury, Dave Smith, Christian Spieler, Antoine Verheijen,
//   Paul von Behren, Rich Wales, Mike White
//
// This software is provided "as is," without warranty of any kind, express
// or implied.  In no event shall Info-ZIP or its contributors be held liable
// for any direct, indirect, incidental, special or consequential damages
// arising out of the use of or inability to use this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
//    1. Redistributions of source code must retain the above copyright notice,
//       definition, disclaimer, and this list of conditions.
//
//    2. Redistributions in binary form must reproduce the above copyright
//       notice, definition, disclaimer, and this list of conditions in
//       documentation and/or other materials provided with the distribution.
//
//    3. Altered versions--including, but not limited to, ports to new operating
//       systems, existing ports with new graphical interfaces, and dynamic,
//       shared, or static library versions--must be plainly marked as such
//       and must not be misrepresented as being the original source.  Such
//       altered versions also must not be misrepresented as being Info-ZIP
//       releases--including, but not limited to, labeling of the altered
//       versions with the names "Info-ZIP" (or any variation thereof, including,
//       but not limited to, different capitalizations), "Pocket UnZip," "WiZ"
//       or "MacZip" without the explicit permission of Info-ZIP.  Such altered
//       versions are further prohibited from misrepresentative use of the
//       Zip-Bugs or Info-ZIP e-mail addresses or of the Info-ZIP URL(s).
//
//    4. Info-ZIP retains the right to use the names "Info-ZIP," "Zip," "UnZip,"
//       "WiZ," "Pocket UnZip," "Pocket Zip," and "MacZip" for its own source and
//       binary releases.
//


typedef unsigned char uch;      // unsigned 8-bit value
typedef unsigned short ush;     // unsigned 16-bit value
typedef unsigned long ulg;      // unsigned 32-bit value
typedef size_t extent;          // file size
typedef unsigned Pos;   // must be at least 32 bits
typedef unsigned IPos; // A Pos is an index in the character window. Pos is used only for parameter passing

#ifndef EOF
#define EOF (-1)
#endif






                       // Error return values.  The values 0..4 and 12..18 follow the conventions
                       // of PKZIP.   The values 4..10 are all assigned to "insufficient memory"
                       // by PKZIP, so the codes 5..10 are used here for other purposes.
#define ZE_MISS         -1      // used by procname(), zipbare()
#define ZE_OK           0       // success
#define ZE_EOF          2       // unexpected end of zip file
#define ZE_FORM         3       // zip file structure error
#define ZE_MEM          4       // out of memory
#define ZE_LOGIC        5       // internal logic error
#define ZE_BIG          6       // entry too large to split
#define ZE_NOTE         7       // invalid comment format
#define ZE_TEST         8       // zip test (-T) failed or out of memory
#define ZE_ABORT        9       // user interrupt or termination
#define ZE_TEMP         10      // error using a temp file
#define ZE_READ         11      // read or seek error
#define ZE_NONE         12      // nothing to do
#define ZE_NAME         13      // missing or empty zip file
#define ZE_WRITE        14      // error writing to a file
#define ZE_CREAT        15      // couldn't open to write
#define ZE_PARMS        16      // bad command line
#define ZE_OPEN         18      // could not open a specified file to read
#define ZE_MAXERR       18      // the highest error number


                       // internal file attribute
#define UNKNOWN (-1)
#define BINARY  0
#define ASCII   1

#define BEST -1                 // Use best method (deflation or store)
#define STORE 0                 // Store method
#define DEFLATE 8               // Deflation method

#define CRCVAL_INITIAL  0L

                       // MSDOS file or directory attributes
#define MSDOS_HIDDEN_ATTR 0x02
#define MSDOS_DIR_ATTR 0x10

                       // Lengths of headers after signatures in bytes
#define LOCHEAD 26
#define CENHEAD 42
#define ENDHEAD 18

                       // Definitions for extra field handling:
#define EB_HEADSIZE       4     /* length of a extra field block header */
#define EB_LEN            2     /* offset of data length field in header */
#define EB_UT_MINLEN      1     /* minimal UT field contains Flags byte */
#define EB_UT_FLAGS       0     /* byte offset of Flags field */
#define EB_UT_TIME1       1     /* byte offset of 1st time value */
#define EB_UT_FL_MTIME    (1 << 0)      /* mtime present */
#define EB_UT_FL_ATIME    (1 << 1)      /* atime present */
#define EB_UT_FL_CTIME    (1 << 2)      /* ctime present */
#define EB_UT_LEN(n)      (EB_UT_MINLEN + 4 * (n))
#define EB_L_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(3))
#define EB_C_UT_SIZE    (EB_HEADSIZE + EB_UT_LEN(1))


                       // Macros for writing machine integers to little-endian format
#define PUTSH(a,f) {char _putsh_c=(char)((a)&0xff); wfunc(param,&_putsh_c,1); _putsh_c=(char)((a)>>8); wfunc(param,&_putsh_c,1);}
#define PUTLG(a,f) {PUTSH((a) & 0xffff,(f)) PUTSH((a) >> 16,(f))}


                       // -- Structure of a ZIP file --
                       // Signatures for zip file information headers
#define LOCSIG     0x04034b50L
#define CENSIG     0x02014b50L
#define ENDSIG     0x06054b50L
#define EXTLOCSIG  0x08074b50L


#define MIN_MATCH  3
#define MAX_MATCH  258
                       // The minimum and maximum match lengths


#define WSIZE  (0x8000)
                       // Maximum window size = 32K. If you are really short of memory, compile
                       // with a smaller WSIZE but this reduces the compression ratio for files
                       // of size > WSIZE. WSIZE must be a power of two in the current implementation.
                       //

#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
                       // Minimum amount of lookahead, except at the end of the input file.
                       // See deflate.c for comments about the MIN_MATCH+1.
                       //

#define MAX_DIST  (WSIZE-MIN_LOOKAHEAD)
                       // In order to simplify the code, particularly on 16 bit machines, match
                       // distances are limited to MAX_DIST instead of WSIZE.
                       //


#define ZIP_HANDLE   1
#define ZIP_FILENAME 2
#define ZIP_MEMORY   3
#define ZIP_FOLDER   4



                       // ===========================================================================
                       // Constants
                       //

#define MAX_BITS 15
                       // All codes must not exceed MAX_BITS bits

#define MAX_BL_BITS 7
                       // Bit length codes must not exceed MAX_BL_BITS bits

#define LENGTH_CODES 29
                       // number of length codes, not counting the special END_BLOCK code

#define LITERALS  256
                       // number of literal bytes 0..255

#define END_BLOCK 256
                       // end of block literal code

#define L_CODES (LITERALS+1+LENGTH_CODES)
                       // number of Literal or Length codes, including the END_BLOCK code

#define D_CODES   30
                       // number of distance codes

#define BL_CODES  19
                       // number of codes used to transfer the bit lengths


#define STORED_BLOCK 0
#define STATIC_TREES 1
#define DYN_TREES    2
                       // The three kinds of block type

#define LIT_BUFSIZE  0x8000
#define DIST_BUFSIZE  LIT_BUFSIZE
                       // Sizes of match buffers for literals/lengths and distances.  There are
                       // 4 reasons for limiting LIT_BUFSIZE to 64K:
                       //   - frequencies can be kept in 16 bit counters
                       //   - if compression is not successful for the first block, all input data is
                       //     still in the window so we can still emit a stored block even when input
                       //     comes from standard input.  (This can also be done for all blocks if
                       //     LIT_BUFSIZE is not greater than 32K.)
                       //   - if compression is not successful for a file smaller than 64K, we can
                       //     even emit a stored file instead of a stored block (saving 5 bytes).
                       //   - creating new Huffman trees less frequently may not provide fast
                       //     adaptation to changes in the input data statistics. (Take for
                       //     example a binary file with poorly compressible code followed by
                       //     a highly compressible string table.) Smaller buffer sizes give
                       //     fast adaptation but have of course the overhead of transmitting trees
                       //     more frequently.
                       //   - I can't count above 4
                       // The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
                       // memory at the expense of compression). Some optimizations would be possible
                       // if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
                       //

#define REP_3_6      16
                       // repeat previous bit length 3-6 times (2 bits of repeat count)

#define REPZ_3_10    17
                       // repeat a zero length 3-10 times  (3 bits of repeat count)

#define REPZ_11_138  18
                       // repeat a zero length 11-138 times  (7 bits of repeat count)

#define HEAP_SIZE (2*L_CODES+1)
                       // maximum heap size


                       // ===========================================================================
                       // Local data used by the "bit string" routines.
                       //

#define Buf_size (8 * 2*sizeof(char))
                       // Number of bits used within bi_buf. (bi_buf may be implemented on
                       // more than 16 bits on some systems.)

                       // Output a 16 bit value to the bit stream, lower (oldest) byte first
#define PUTSHORT(state,w) \
{ if (state.bs.out_offset >= state.bs.out_size-1) \
    state.flush_outbuf(state.param,state.bs.out_buf, &state.bs.out_offset); \
  state.bs.out_buf[state.bs.out_offset++] = (char) ((w) & 0xff); \
  state.bs.out_buf[state.bs.out_offset++] = (char) ((ush)(w) >> 8); \
}

#define PUTBYTE(state,b) \
{ if (state.bs.out_offset >= state.bs.out_size) \
    state.flush_outbuf(state.param,state.bs.out_buf, &state.bs.out_offset); \
  state.bs.out_buf[state.bs.out_offset++] = (char) (b); \
}

                       // DEFLATE.CPP HEADER

#define HASH_BITS  15
                       // For portability to 16 bit machines, do not use values above 15.

#define HASH_SIZE (unsigned)(1<<HASH_BITS)
#define HASH_MASK (HASH_SIZE-1)
#define WMASK     (WSIZE-1)
                       // HASH_SIZE and WSIZE must be powers of two

#define NIL 0
                       // Tail of hash chains

#define FAST 4
#define SLOW 2
                       // speed options for the general purpose bit flag

#define TOO_FAR 4096
                       // Matches of length 3 are discarded if their distance exceeds TOO_FAR



#define EQUAL 0
                       // result of memcmp for equal strings


                       // ===========================================================================
                       // Local data used by the "longest match" routines.

#define H_SHIFT  ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
                       // Number of bits by which ins_h and del_h must be shifted at each
                       // input step. It must be such that after MIN_MATCH steps, the oldest
                       // byte no longer takes part in the hash key, that is:
                       //   H_SHIFT * MIN_MATCH >= HASH_BITS

#define max_insert_length  max_lazy_match
                       // Insert new strings in the hash table only if the match length
                       // is not greater than this length. This saves time but degrades compression.
                       // max_insert_length is used only for compression levels <= 3.



const int extra_lbits[LENGTH_CODES] // extra bits for each length code
= {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};

const int extra_dbits[D_CODES] // extra bits for each distance code
= {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};

const int extra_blbits[BL_CODES]// extra bits for each bit length code
= {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};

const uch bl_order[BL_CODES] = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
// The lengths of the bit length codes are sent in order of decreasing
// probability, to avoid transmitting the lengths for unused bit length codes.


typedef struct config
{
    ush good_length; // reduce lazy search above this match length
    ush max_lazy;    // do not perform lazy search above this match length
    ush nice_length; // quit search above this match length
    ush max_chain;
} config;

// Values for max_lazy_match, good_match, nice_match and max_chain_length,
// depending on the desired pack level (0..9). The values given below have
// been tuned to exclude worst case performance for pathological files.
// Better values may be found for specific files.
//

const config configuration_table[10] = {
    //  good lazy nice chain
    {0,    0,  0,    0},  // 0 store only
    {4,    4,  8,    4},  // 1 maximum speed, no lazy matches
    {4,    5, 16,    8},  // 2
    {4,    6, 32,   32},  // 3
    {4,    4, 16,   16},  // 4 lazy matches */
    {8,   16, 32,   32},  // 5
    {8,   16, 128, 128},  // 6
    {8,   32, 128, 256},  // 7
    {32, 128, 258, 1024}, // 8
    {32, 258, 258, 4096}};// 9 maximum compression */

                          // Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
                          // For deflate_fast() (levels <= 3) good is ignored and lazy has a different meaning.







                          // Data structure describing a single value and its code string.
typedef struct ct_data
{
    union
    {
        ush  freq;       // frequency count
        ush  code;       // bit string
    } fc;
    union
    {
        ush  dad;        // father node in Huffman tree
        ush  len;        // length of bit string
    } dl;
} ct_data;

typedef struct tree_desc
{
    ct_data *dyn_tree;      // the dynamic tree
    ct_data *static_tree;   // corresponding static tree or NULL
    const int *extra_bits;  // extra bits for each code or NULL
    int     extra_base;     // base index for extra_bits
    int     elems;          // max number of elements in the tree
    int     max_length;     // max bit length for the codes
    int     max_code;       // largest code with non zero frequency
} tree_desc;




class TTreeState
{
public:
    TTreeState();

    ct_data dyn_ltree[HEAP_SIZE];    // literal and length tree
    ct_data dyn_dtree[2 * D_CODES + 1];  // distance tree
    ct_data static_ltree[L_CODES + 2]; // the static literal tree...
                                       // ... Since the bit lengths are imposed, there is no need for the L_CODES
                                       // extra codes used during heap construction. However the codes 286 and 287
                                       // are needed to build a canonical tree (see ct_init below).
    ct_data static_dtree[D_CODES]; // the static distance tree...
                                   // ... (Actually a trivial tree since all codes use 5 bits.)
    ct_data bl_tree[2 * BL_CODES + 1];  // Huffman tree for the bit lengths

    tree_desc l_desc;
    tree_desc d_desc;
    tree_desc bl_desc;

    ush bl_count[MAX_BITS + 1];  // number of codes at each bit length for an optimal tree

    int heap[2 * L_CODES + 1]; // heap used to build the Huffman trees
    int heap_len;               // number of elements in the heap
    int heap_max;               // element of largest frequency
                                // The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
                                // The same heap array is used to build all trees.

    uch depth[2 * L_CODES + 1];
    // Depth of each subtree used as tie breaker for trees of equal frequency

    uch length_code[MAX_MATCH - MIN_MATCH + 1];
    // length code for each normalized match length (0 == MIN_MATCH)

    uch dist_code[512];
    // distance codes. The first 256 values correspond to the distances
    // 3 .. 258, the last 256 values correspond to the top 8 bits of
    // the 15 bit distances.

    int base_length[LENGTH_CODES];
    // First normalized length for each code (0 = MIN_MATCH)

    int base_dist[D_CODES];
    // First normalized distance for each code (0 = distance of 1)

    uch l_buf[LIT_BUFSIZE];  // buffer for literals/lengths
    ush d_buf[DIST_BUFSIZE]; // buffer for distances

    uch flag_buf[(LIT_BUFSIZE / 8)];
    // flag_buf is a bit array distinguishing literals from lengths in
    // l_buf, and thus indicating the presence or absence of a distance.

    unsigned last_lit;    // running index in l_buf
    unsigned last_dist;   // running index in d_buf
    unsigned last_flags;  // running index in flag_buf
    uch flags;            // current flags not yet saved in flag_buf
    uch flag_bit;         // current bit used in flags
                          // bits are filled in flags starting at bit 0 (least significant).
                          // Note: these flags are overkill in the current code since we don't
                          // take advantage of DIST_BUFSIZE == LIT_BUFSIZE.

    ulg opt_len;          // bit length of current block with optimal trees
    ulg static_len;       // bit length of current block with static trees

    ulg cmpr_bytelen;     // total byte length of compressed file
    ulg cmpr_len_bits;    // number of bits past 'cmpr_bytelen'

    ulg input_len;        // total byte length of input file
                          // input_len is for debugging only since we can get it by other means.

    ush *file_type;       // pointer to UNKNOWN, BINARY or ASCII
                          //  int *file_method;     // pointer to DEFLATE or STORE
};

TTreeState::TTreeState()
{
    tree_desc a = {dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES, MAX_BITS, 0};  l_desc = a;
    tree_desc b = {dyn_dtree, static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS, 0};  d_desc = b;
    tree_desc c = {bl_tree, NULL,       extra_blbits, 0,         BL_CODES, MAX_BL_BITS, 0};  bl_desc = c;
    last_lit = 0;
    last_dist = 0;
    last_flags = 0;
}



class TBitState
{
public:

    int flush_flg;
    //
    unsigned bi_buf;
    // Output buffer. bits are inserted starting at the bottom (least significant
    // bits). The width of bi_buf must be at least 16 bits.
    int bi_valid;
    // Number of valid bits in bi_buf.  All bits above the last valid bit
    // are always zero.
    char *out_buf;
    // Current output buffer.
    unsigned out_offset;
    // Current offset in output buffer.
    // On 16 bit machines, the buffer is limited to 64K.
    unsigned out_size;
    // Size of current output buffer
    ulg bits_sent;   // bit length of the compressed data  only needed for debugging???
};







class TDeflateState
{
public:
    TDeflateState()
    {
        window_size = 0;
    }

    uch    window[2L * WSIZE];
    // Sliding window. Input bytes are read into the second half of the window,
    // and move to the first half later to keep a dictionary of at least WSIZE
    // bytes. With this organization, matches are limited to a distance of
    // WSIZE-MAX_MATCH bytes, but this ensures that IO is always
    // performed with a length multiple of the block size. Also, it limits
    // the window size to 64K, which is quite useful on MSDOS.
    // To do: limit the window size to WSIZE+CBSZ if SMALL_MEM (the code would
    // be less efficient since the data would have to be copied WSIZE/CBSZ times)
    Pos    prev[WSIZE];
    // Link to older string with same hash index. To limit the size of this
    // array to 64K, this link is maintained only for the last 32K strings.
    // An index in this array is thus a window index modulo 32K.
    Pos    head[HASH_SIZE];
    // Heads of the hash chains or NIL. If your compiler thinks that
    // HASH_SIZE is a dynamic value, recompile with -DDYN_ALLOC.

    ulg window_size;
    // window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
    // input file length plus MIN_LOOKAHEAD.

    long block_start;
    // window position at the beginning of the current output block. Gets
    // negative when the window is moved backwards.

    int sliding;
    // Set to false when the input file is already in memory

    unsigned ins_h;  // hash index of string to be inserted

    unsigned int prev_length;
    // Length of the best match at previous step. Matches not greater than this
    // are discarded. This is used in the lazy match evaluation.

    unsigned strstart;         // start of string to insert
    unsigned match_start; // start of matching string
    int      eofile;           // flag set at end of input file
    unsigned lookahead;        // number of valid bytes ahead in window

    unsigned max_chain_length;
    // To speed up deflation, hash chains are never searched beyond this length.
    // A higher limit improves compression ratio but degrades the speed.

    unsigned int max_lazy_match;
    // Attempt to find a better match only when the current match is strictly
    // smaller than this value. This mechanism is used only for compression
    // levels >= 4.

    unsigned good_match;
    // Use a faster search when the previous match is longer than this

    int nice_match; // Stop searching when current match exceeds this
};

typedef long lutime_t;       // define it ourselves since we don't include time.h

typedef struct iztimes
{
    lutime_t atime, mtime, ctime;
} iztimes; // access, modify, create times

typedef struct zlist
{
    ush vem, ver, flg, how;       // See central header in zipfile.c for what vem..off are
    ulg tim, crc, siz, len;
    extent nam, ext, cext, com;   // offset of ext must be >= LOCHEAD
    ush dsk, att, lflg;           // offset of lflg must be >= LOCHEAD
    ulg atx, off;
    char name[MAX_PATH];          // File name in zip file
    char *extra;                  // Extra field (set only if ext != 0)
    char *cextra;                 // Extra in central (set only if cext != 0)
    char *comment;                // Comment (set only if com != 0)
    char iname[MAX_PATH];         // Internal file name after cleanup
    char zname[MAX_PATH];         // External version of internal name
    int mark;                     // Marker for files to operate on
    int trash;                    // Marker for files to delete
    int dosflag;                  // Set to force MSDOS file attributes
    struct zlist *nxt;        // Pointer to next header in list
} TZipFileInfo;


struct TState;
typedef unsigned( *READFUNC )(TState &state, char *buf, unsigned size);
typedef unsigned( *FLUSHFUNC )(void *param, const char *buf, unsigned *size);
typedef unsigned( *WRITEFUNC )(void *param, const char *buf, unsigned size);
struct TState
{
    void *param;
    int level; bool seekable;
    READFUNC readfunc; FLUSHFUNC flush_outbuf;
    TTreeState ts; TBitState bs; TDeflateState ds;
    const char *err;
};




// ----------------------------------------------------------------------
// some windows<->linux portability things
#ifdef ZIP_STD
void filetime2dosdatetime( const FILETIME ft, WORD *dosdate, WORD *dostime )
{
    struct tm *st = gmtime( &ft );
    *dosdate = (ush)(((st->tm_year + 1900 - 1980) & 0x7f) << 9);
    *dosdate |= (ush)((st->tm_mon & 0xf) << 5);
    *dosdate |= (ush)((st->tm_mday & 0x1f));
    *dostime = (ush)((st->tm_hour & 0x1f) << 11);
    *dostime |= (ush)((st->tm_min & 0x3f) << 5);
    *dostime |= (ush)((st->tm_sec * 2) & 0x1f);
}

void GetNow( lutime_t *ft, WORD *dosdate, WORD *dostime )
{
    time_t tm = time( 0 );
    filetime2dosdatetime( tm, dosdate, dostime );
    *ft = (lutime_t)tm;
}

DWORD GetFilePosZ( HANDLE hfout )
{
    struct stat st; fstat( fileno( hfout ), &st );
    if((st.st_mode&S_IFREG) == 0) return 0xFFFFFFFF;
    return ftell( hfout );
}

ZRESULT GetFileInfo( FILE *hf, ulg *attr, long *size, iztimes *times, ulg *timestamp )
{ // The handle must be a handle to a file
  // The date and time is returned in a long with the date most significant to allow
  // unsigned integer comparison of absolute times. The attributes have two
  // high bytes unix attr, and two low bytes a mapping of that to DOS attr.
    struct stat bhi; int res = fstat( fileno( hf ), &bhi ); if(res == -1) return ZR_NOFILE;
    ulg fa = bhi.st_mode; ulg a = 0;
    // Zip uses the lower word for its interpretation of windows stuff
    if((fa&S_IWUSR) == 0) a |= 0x01;
    if(S_ISDIR( fa )) a |= 0x10;
    // It uses the upper word for standard unix attr
    a |= ((fa & 0xFFFF) << 16);
    //
    if(attr != NULL) *attr = a;
    if(size != NULL) *size = bhi.st_size;
    if(times != NULL)
    {
        times->atime = (lutime_t)bhi.st_atime;
        times->mtime = (lutime_t)bhi.st_mtime;
        times->ctime = (lutime_t)bhi.st_ctime;
    }
    if(timestamp != NULL)
    {
        ush dosdate, dostime;
        filetime2dosdatetime( bhi.st_mtime, &dosdate, &dostime );
        *timestamp = (ush)dostime | (((ulg)dosdate) << 16);
    }
    return ZR_OK;
}


// ----------------------------------------------------------------------
#else
void filetime2dosdatetime( const FILETIME ft, WORD *dosdate, WORD *dostime )
{ // date: bits 0-4 are day of month 1-31. Bits 5-8 are month 1..12. Bits 9-15 are year-1980
  // time: bits 0-4 are seconds/2, bits 5-10 are minute 0..59. Bits 11-15 are hour 0..23
    SYSTEMTIME st; FileTimeToSystemTime( &ft, &st );
    *dosdate = (WORD)(((st.wYear - 1980) & 0x7f) << 9);
    *dosdate |= (WORD)((st.wMonth & 0xf) << 5);
    *dosdate |= (WORD)((st.wDay & 0x1f));
    *dostime = (WORD)((st.wHour & 0x1f) << 11);
    *dostime |= (WORD)((st.wMinute & 0x3f) << 5);
    *dostime |= (WORD)((st.wSecond * 2) & 0x1f);
}

lutime_t filetime2timet( const FILETIME ft )
{
    LONGLONG i = *(LONGLONG*)&ft;
    return (lutime_t)((i - 116444736000000000LL) / 10000000LL);
}

void GetNow( lutime_t *pft, WORD *dosdate, WORD *dostime )
{
    SYSTEMTIME st; GetLocalTime( &st );
    FILETIME ft;   SystemTimeToFileTime( &st, &ft );
    filetime2dosdatetime( ft, dosdate, dostime );
    *pft = filetime2timet( ft );
}

DWORD GetFilePosZ( HANDLE hfout )
{
    return SetFilePointer( hfout, 0, 0, FILE_CURRENT );
}


ZRESULT GetFileInfo( HANDLE hf, ulg *attr, long *size, iztimes *times, ulg *timestamp )
{ // The handle must be a handle to a file
  // The date and time is returned in a long with the date most significant to allow
  // unsigned integer comparison of absolute times. The attributes have two
  // high bytes unix attr, and two low bytes a mapping of that to DOS attr.
  //struct stat s; int res=stat(fn,&s); if (res!=0) return false;
  // translate windows file attributes into zip ones.
    BY_HANDLE_FILE_INFORMATION bhi; BOOL res = GetFileInformationByHandle( hf, &bhi );
    if(!res) return ZR_NOFILE;
    DWORD fa = bhi.dwFileAttributes; ulg a = 0;
    // Zip uses the lower word for its interpretation of windows stuff
    if(fa&FILE_ATTRIBUTE_READONLY) a |= 0x01;
    if(fa&FILE_ATTRIBUTE_HIDDEN)   a |= 0x02;
    if(fa&FILE_ATTRIBUTE_SYSTEM)   a |= 0x04;
    if(fa&FILE_ATTRIBUTE_DIRECTORY)a |= 0x10;
    if(fa&FILE_ATTRIBUTE_ARCHIVE)  a |= 0x20;
    // It uses the upper word for standard unix attr, which we manually construct
    if(fa&FILE_ATTRIBUTE_DIRECTORY)a |= 0x40000000;  // directory
    else a |= 0x80000000;  // normal file
    a |= 0x01000000;      // readable
    if(fa&FILE_ATTRIBUTE_READONLY)
    {
    }
    else a |= 0x00800000; // writeable
                          // now just a small heuristic to check if it's an executable:
    DWORD red, hsize = GetFileSize( hf, NULL ); if(hsize>40)
    {
        SetFilePointer( hf, 0, NULL, FILE_BEGIN ); unsigned short magic; ReadFile( hf, &magic, sizeof( magic ), &red, NULL );
        SetFilePointer( hf, 36, NULL, FILE_BEGIN ); unsigned long hpos;  ReadFile( hf, &hpos, sizeof( hpos ), &red, NULL );
        if(magic == 0x54AD && hsize>hpos + 4 + 20 + 28)
        {
            SetFilePointer( hf, hpos, NULL, FILE_BEGIN ); unsigned long signature; ReadFile( hf, &signature, sizeof( signature ), &red, NULL );
            if(signature == IMAGE_DOS_SIGNATURE || signature == IMAGE_OS2_SIGNATURE
                || signature == IMAGE_OS2_SIGNATURE_LE || signature == IMAGE_NT_SIGNATURE)
            {
                a |= 0x00400000; // executable
            }
        }
    }
    //
    if(attr != NULL) *attr = a;
    if(size != NULL) *size = hsize;
    if(times != NULL)
    { // lutime_t is 32bit number of seconds elapsed since 0:0:0GMT, Jan1, 1970.
      // but FILETIME is 64bit number of 100-nanosecs since Jan1, 1601
        times->atime = filetime2timet( bhi.ftLastAccessTime );
        times->mtime = filetime2timet( bhi.ftLastWriteTime );
        times->ctime = filetime2timet( bhi.ftCreationTime );
    }
    if(timestamp != NULL)
    {
        WORD dosdate, dostime;
        filetime2dosdatetime( bhi.ftLastWriteTime, &dosdate, &dostime );
        *timestamp = (WORD)dostime | (((DWORD)dosdate) << 16);
    }
    return ZR_OK;
}
#endif
// ----------------------------------------------------------------------





void Assert( TState &state, bool cond, const char *msg )
{
    if(cond) return;
    state.err = msg;
}
void Trace( const char *x, ... )
{
    va_list paramList; va_start( paramList, x ); paramList; va_end( paramList );
}
void Tracec( bool, const char *x, ... )
{
    va_list paramList; va_start( paramList, x ); paramList; va_end( paramList );
}



// ===========================================================================
// Local (static) routines in this file.
//

void init_block( TState & );
void pqdownheap( TState &, ct_data *tree, int k );
void gen_bitlen( TState &, tree_desc *desc );
void gen_codes( TState &state, ct_data *tree, int max_code );
void build_tree( TState &, tree_desc *desc );
void scan_tree( TState &, ct_data *tree, int max_code );
void send_tree( TState &state, ct_data *tree, int max_code );
int  build_bl_tree( TState & );
void send_all_trees( TState &state, int lcodes, int dcodes, int blcodes );
void compress_block( TState &state, ct_data *ltree, ct_data *dtree );
void set_file_type( TState & );
void send_bits( TState &state, int value, int length );
unsigned bi_reverse( unsigned code, int len );
void bi_windup( TState &state );
void copy_block( TState &state, char *buf, unsigned len, int header );


#define send_code(state, c, tree) send_bits(state, tree[c].fc.code, tree[c].dl.len)
// Send a code of the given tree. c and tree must not have side effects

// alternatively...
//#define send_code(state, c, tree)
//     { if (state.verbose>1) fprintf(stderr,"\ncd %3d ",(c));
//       send_bits(state, tree[c].fc.code, tree[c].dl.len); }

#define d_code(dist) ((dist) < 256 ? state.ts.dist_code[dist] : state.ts.dist_code[256+((dist)>>7)])
// Mapping from a distance to a distance code. dist is the distance - 1 and
// must not have side effects. dist_code[256] and dist_code[257] are never used.

#define Max(a,b) (a >= b ? a : b)
/* the arguments must not have side effects */

/* ===========================================================================
* Allocate the match buffer, initialize the various tables and save the
* location of the internal file attribute (ascii/binary) and method
* (DEFLATE/STORE).
*/
void ct_init( TState &state, ush *attr )
{
    int n;        /* iterates over tree elements */
    int bits;     /* bit counter */
    int length;   /* length value */
    int code;     /* code value */
    int dist;     /* distance index */

    state.ts.file_type = attr;
    //state.ts.file_method = method;
    state.ts.cmpr_bytelen = state.ts.cmpr_len_bits = 0L;
    state.ts.input_len = 0L;

    if(state.ts.static_dtree[0].dl.len != 0) return; /* ct_init already called */

                                                     /* Initialize the mapping length (0..255) -> length code (0..28) */
    length = 0;
    for(code = 0; code < LENGTH_CODES - 1; code++)
    {
        state.ts.base_length[code] = length;
        for(n = 0; n < (1 << extra_lbits[code]); n++)
        {
            state.ts.length_code[length++] = (uch)code;
        }
    }
    Assert( state, length == 256, "ct_init: length != 256" );
    /* Note that the length 255 (match length 258) can be represented
    * in two different ways: code 284 + 5 bits or code 285, so we
    * overwrite length_code[255] to use the best encoding:
    */
    state.ts.length_code[length - 1] = (uch)code;

    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
    dist = 0;
    for(code = 0; code < 16; code++)
    {
        state.ts.base_dist[code] = dist;
        for(n = 0; n < (1 << extra_dbits[code]); n++)
        {
            state.ts.dist_code[dist++] = (uch)code;
        }
    }
    Assert( state, dist == 256, "ct_init: dist != 256" );
    dist >>= 7; /* from now on, all distances are divided by 128 */
    for(; code < D_CODES; code++)
    {
        state.ts.base_dist[code] = dist << 7;
        for(n = 0; n < (1 << (extra_dbits[code] - 7)); n++)
        {
            state.ts.dist_code[256 + dist++] = (uch)code;
        }
    }
    Assert( state, dist == 256, "ct_init: 256+dist != 512" );

    /* Construct the codes of the static literal tree */
    for(bits = 0; bits <= MAX_BITS; bits++) state.ts.bl_count[bits] = 0;
    n = 0;
    while(n <= 143) state.ts.static_ltree[n++].dl.len = 8, state.ts.bl_count[8]++;
    while(n <= 255) state.ts.static_ltree[n++].dl.len = 9, state.ts.bl_count[9]++;
    while(n <= 279) state.ts.static_ltree[n++].dl.len = 7, state.ts.bl_count[7]++;
    while(n <= 287) state.ts.static_ltree[n++].dl.len = 8, state.ts.bl_count[8]++;
    /* fc.codes 286 and 287 do not exist, but we must include them in the
    * tree construction to get a canonical Huffman tree (longest code
    * all ones)
    */
    gen_codes( state, (ct_data *)state.ts.static_ltree, L_CODES + 1 );

    /* The static distance tree is trivial: */
    for(n = 0; n < D_CODES; n++)
    {
        state.ts.static_dtree[n].dl.len = 5;
        state.ts.static_dtree[n].fc.code = (ush)bi_reverse( n, 5 );
    }

    /* Initialize the first block of the first file: */
    init_block( state );
}

/* ===========================================================================
* Initialize a new block.
*/
void init_block( TState &state )
{
    int n; /* iterates over tree elements */

           /* Initialize the trees. */
    for(n = 0; n < L_CODES; n++) state.ts.dyn_ltree[n].fc.freq = 0;
    for(n = 0; n < D_CODES; n++) state.ts.dyn_dtree[n].fc.freq = 0;
    for(n = 0; n < BL_CODES; n++) state.ts.bl_tree[n].fc.freq = 0;

    state.ts.dyn_ltree[END_BLOCK].fc.freq = 1;
    state.ts.opt_len = state.ts.static_len = 0L;
    state.ts.last_lit = state.ts.last_dist = state.ts.last_flags = 0;
    state.ts.flags = 0; state.ts.flag_bit = 1;
}

#define SMALLEST 1
/* Index within the heap array of least frequent node in the Huffman tree */


/* ===========================================================================
* Remove the smallest element from the heap and recreate the heap with
* one less element. Updates heap and heap_len.
*/
#define pqremove(tree, top) \
{\
    top = state.ts.heap[SMALLEST]; \
    state.ts.heap[SMALLEST] = state.ts.heap[state.ts.heap_len--]; \
    pqdownheap(state,tree, SMALLEST); \
}

/* ===========================================================================
* Compares to subtrees, using the tree depth as tie breaker when
* the subtrees have equal frequency. This minimizes the worst case length.
*/
#define smaller(tree, n, m) \
   (tree[n].fc.freq < tree[m].fc.freq || \
   (tree[n].fc.freq == tree[m].fc.freq && state.ts.depth[n] <= state.ts.depth[m]))

/* ===========================================================================
* Restore the heap property by moving down the tree starting at node k,
* exchanging a node with the smallest of its two sons if necessary, stopping
* when the heap property is re-established (each father smaller than its
* two sons).
*/
void pqdownheap( TState &state, ct_data *tree, int k )
{
    int v = state.ts.heap[k];
    int j = k << 1;  /* left son of k */
    int htemp;       /* required because of bug in SASC compiler */

    while(j <= state.ts.heap_len)
    {
        /* Set j to the smallest of the two sons: */
        if(j < state.ts.heap_len && smaller( tree, state.ts.heap[j + 1], state.ts.heap[j] )) j++;

        /* Exit if v is smaller than both sons */
        htemp = state.ts.heap[j];
        if(smaller( tree, v, htemp )) break;

        /* Exchange v with the smallest son */
        state.ts.heap[k] = htemp;
        k = j;

        /* And continue down the tree, setting j to the left son of k */
        j <<= 1;
    }
    state.ts.heap[k] = v;
}

/* ===========================================================================
* Compute the optimal bit lengths for a tree and update the total bit length
* for the current block.
* IN assertion: the fields freq and dad are set, heap[heap_max] and
*    above are the tree nodes sorted by increasing frequency.
* OUT assertions: the field len is set to the optimal bit length, the
*     array bl_count contains the frequencies for each bit length.
*     The length opt_len is updated; static_len is also updated if stree is
*     not null.
*/
void gen_bitlen( TState &state, tree_desc *desc )
{
    ct_data *tree = desc->dyn_tree;
    const int *extra = desc->extra_bits;
    int base = desc->extra_base;
    int max_code = desc->max_code;
    int max_length = desc->max_length;
    ct_data *stree = desc->static_tree;
    int h;              /* heap index */
    int n, m;           /* iterate over the tree elements */
    int bits;           /* bit length */
    int xbits;          /* extra bits */
    ush f;              /* frequency */
    int overflow = 0;   /* number of elements with bit length too large */

    for(bits = 0; bits <= MAX_BITS; bits++) state.ts.bl_count[bits] = 0;

    /* In a first pass, compute the optimal bit lengths (which may
    * overflow in the case of the bit length tree).
    */
    tree[state.ts.heap[state.ts.heap_max]].dl.len = 0; /* root of the heap */

    for(h = state.ts.heap_max + 1; h < HEAP_SIZE; h++)
    {
        n = state.ts.heap[h];
        bits = tree[tree[n].dl.dad].dl.len + 1;
        if(bits > max_length) bits = max_length, overflow++;
        tree[n].dl.len = (ush)bits;
        /* We overwrite tree[n].dl.dad which is no longer needed */

        if(n > max_code) continue; /* not a leaf node */

        state.ts.bl_count[bits]++;
        xbits = 0;
        if(n >= base) xbits = extra[n - base];
        f = tree[n].fc.freq;
        state.ts.opt_len += (ulg)f * (bits + xbits);
        if(stree) state.ts.static_len += (ulg)f * (stree[n].dl.len + xbits);
    }
    if(overflow == 0) return;

    Trace( "\nbit length overflow\n" );
    /* This happens for example on obj2 and pic of the Calgary corpus */

    /* Find the first bit length which could increase: */
    do
    {
        bits = max_length - 1;
        while(state.ts.bl_count[bits] == 0) bits--;
        state.ts.bl_count[bits]--;           /* move one leaf down the tree */
        state.ts.bl_count[bits + 1] += (ush)2; /* move one overflow item as its brother */
        state.ts.bl_count[max_length]--;
        /* The brother of the overflow item also moves one step up,
        * but this does not affect bl_count[max_length]
        */
        overflow -= 2;
    }
    while(overflow > 0);

    /* Now recompute all bit lengths, scanning in increasing frequency.
    * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
    * lengths instead of fixing only the wrong ones. This idea is taken
    * from 'ar' written by Haruhiko Okumura.)
    */
    for(bits = max_length; bits != 0; bits--)
    {
        n = state.ts.bl_count[bits];
        while(n != 0)
        {
            m = state.ts.heap[--h];
            if(m > max_code) continue;
            if(tree[m].dl.len != (ush)bits)
            {
                Trace( "code %d bits %d->%d\n", m, tree[m].dl.len, bits );
                state.ts.opt_len += ((long)bits - (long)tree[m].dl.len)*(long)tree[m].fc.freq;
                tree[m].dl.len = (ush)bits;
            }
            n--;
        }
    }
}

/* ===========================================================================
* Generate the codes for a given tree and bit counts (which need not be
* optimal).
* IN assertion: the array bl_count contains the bit length statistics for
* the given tree and the field len is set for all tree elements.
* OUT assertion: the field code is set for all tree elements of non
*     zero code length.
*/
void gen_codes( TState &state, ct_data *tree, int max_code )
{
    ush next_code[MAX_BITS + 1]; /* next code value for each bit length */
    ush code = 0;              /* running code value */
    int bits;                  /* bit index */
    int n;                     /* code index */

                               /* The distribution counts are first used to generate the code values
                               * without bit reversal.
                               */
    for(bits = 1; bits <= MAX_BITS; bits++)
    {
        next_code[bits] = code = (ush)((code + state.ts.bl_count[bits - 1]) << 1);
    }
    /* Check that the bit counts in bl_count are consistent. The last code
    * must be all ones.
    */
    Assert( state, code + state.ts.bl_count[MAX_BITS] - 1 == (1 << ((ush)MAX_BITS)) - 1,
        "inconsistent bit counts" );
    Trace( "\ngen_codes: max_code %d ", max_code );

    for(n = 0; n <= max_code; n++)
    {
        int len = tree[n].dl.len;
        if(len == 0) continue;
        /* Now reverse the bits */
        tree[n].fc.code = (ush)bi_reverse( next_code[len]++, len );

        //Tracec(tree != state.ts.static_ltree, "\nn %3d %c l %2d c %4x (%x) ", n, (isgraph(n) ? n : ' '), len, tree[n].fc.code, next_code[len]-1);
    }
}

/* ===========================================================================
* Construct one Huffman tree and assigns the code bit strings and lengths.
* Update the total bit length for the current block.
* IN assertion: the field freq is set for all tree elements.
* OUT assertions: the fields len and code are set to the optimal bit length
*     and corresponding code. The length opt_len is updated; static_len is
*     also updated if stree is not null. The field max_code is set.
*/
void build_tree( TState &state, tree_desc *desc )
{
    ct_data *tree = desc->dyn_tree;
    ct_data *stree = desc->static_tree;
    int elems = desc->elems;
    int n, m;          /* iterate over heap elements */
    int max_code = -1; /* largest code with non zero frequency */
    int node = elems;  /* next internal node of the tree */

                       /* Construct the initial heap, with least frequent element in
                       * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
                       * heap[0] is not used.
                       */
    state.ts.heap_len = 0, state.ts.heap_max = HEAP_SIZE;

    for(n = 0; n < elems; n++)
    {
        if(tree[n].fc.freq != 0)
        {
            state.ts.heap[++state.ts.heap_len] = max_code = n;
            state.ts.depth[n] = 0;
        }
        else
        {
            tree[n].dl.len = 0;
        }
    }

    /* The pkzip format requires that at least one distance code exists,
    * and that at least one bit should be sent even if there is only one
    * possible code. So to avoid special checks later on we force at least
    * two codes of non zero frequency.
    */
    while(state.ts.heap_len < 2)
    {
        int newcp = state.ts.heap[++state.ts.heap_len] = (max_code < 2 ? ++max_code : 0);
        tree[newcp].fc.freq = 1;
        state.ts.depth[newcp] = 0;
        state.ts.opt_len--; if(stree) state.ts.static_len -= stree[newcp].dl.len;
        /* new is 0 or 1 so it does not have extra bits */
    }
    desc->max_code = max_code;

    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
    * establish sub-heaps of increasing lengths:
    */
    for(n = state.ts.heap_len / 2; n >= 1; n--) pqdownheap( state, tree, n );

    /* Construct the Huffman tree by repeatedly combining the least two
    * frequent nodes.
    */
    do
    {
        pqremove( tree, n );   /* n = node of least frequency */
        m = state.ts.heap[SMALLEST];  /* m = node of next least frequency */

        state.ts.heap[--state.ts.heap_max] = n; /* keep the nodes sorted by frequency */
        state.ts.heap[--state.ts.heap_max] = m;

        /* Create a new node father of n and m */
        tree[node].fc.freq = (ush)(tree[n].fc.freq + tree[m].fc.freq);
        state.ts.depth[node] = (uch)(Max( state.ts.depth[n], state.ts.depth[m] ) + 1);
        tree[n].dl.dad = tree[m].dl.dad = (ush)node;
        /* and insert the new node in the heap */
        state.ts.heap[SMALLEST] = node++;
        pqdownheap( state, tree, SMALLEST );

    }
    while(state.ts.heap_len >= 2);

    state.ts.heap[--state.ts.heap_max] = state.ts.heap[SMALLEST];

    /* At this point, the fields freq and dad are set. We can now
    * generate the bit lengths.
    */
    gen_bitlen( state, (tree_desc *)desc );

    /* The field len is now set, we can generate the bit codes */
    gen_codes( state, (ct_data *)tree, max_code );
}

/* ===========================================================================
* Scan a literal or distance tree to determine the frequencies of the codes
* in the bit length tree. Updates opt_len to take into account the repeat
* counts. (The contribution of the bit length codes will be added later
* during the construction of bl_tree.)
*/
void scan_tree( TState &state, ct_data *tree, int max_code )
{
    int n;                     /* iterates over all tree elements */
    int prevlen = -1;          /* last emitted length */
    int curlen;                /* length of current code */
    int nextlen = tree[0].dl.len; /* length of next code */
    int count = 0;             /* repeat count of the current code */
    int max_count = 7;         /* max repeat count */
    int min_count = 4;         /* min repeat count */

    if(nextlen == 0) max_count = 138, min_count = 3;
    tree[max_code + 1].dl.len = (ush)-1; /* guard */

    for(n = 0; n <= max_code; n++)
    {
        curlen = nextlen; nextlen = tree[n + 1].dl.len;
        if(++count < max_count && curlen == nextlen)
        {
            continue;
        }
        else if(count < min_count)
        {
            state.ts.bl_tree[curlen].fc.freq = (ush)(state.ts.bl_tree[curlen].fc.freq + count);
        }
        else if(curlen != 0)
        {
            if(curlen != prevlen) state.ts.bl_tree[curlen].fc.freq++;
            state.ts.bl_tree[REP_3_6].fc.freq++;
        }
        else if(count <= 10)
        {
            state.ts.bl_tree[REPZ_3_10].fc.freq++;
        }
        else
        {
            state.ts.bl_tree[REPZ_11_138].fc.freq++;
        }
        count = 0; prevlen = curlen;
        if(nextlen == 0)
        {
            max_count = 138, min_count = 3;
        }
        else if(curlen == nextlen)
        {
            max_count = 6, min_count = 3;
        }
        else
        {
            max_count = 7, min_count = 4;
        }
    }
}

/* ===========================================================================
* Send a literal or distance tree in compressed form, using the codes in
* bl_tree.
*/
void send_tree( TState &state, ct_data *tree, int max_code )
{
    int n;                     /* iterates over all tree elements */
    int prevlen = -1;          /* last emitted length */
    int curlen;                /* length of current code */
    int nextlen = tree[0].dl.len; /* length of next code */
    int count = 0;             /* repeat count of the current code */
    int max_count = 7;         /* max repeat count */
    int min_count = 4;         /* min repeat count */

                               /* tree[max_code+1].dl.len = -1; */  /* guard already set */
    if(nextlen == 0) max_count = 138, min_count = 3;

    for(n = 0; n <= max_code; n++)
    {
        curlen = nextlen; nextlen = tree[n + 1].dl.len;
        if(++count < max_count && curlen == nextlen)
        {
            continue;
        }
        else if(count < min_count)
        {
            do
            {
                send_code( state, curlen, state.ts.bl_tree );
            }
            while(--count != 0);

        }
        else if(curlen != 0)
        {
            if(curlen != prevlen)
            {
                send_code( state, curlen, state.ts.bl_tree ); count--;
            }
            Assert( state, count >= 3 && count <= 6, " 3_6?" );
            send_code( state, REP_3_6, state.ts.bl_tree ); send_bits( state, count - 3, 2 );

        }
        else if(count <= 10)
        {
            send_code( state, REPZ_3_10, state.ts.bl_tree ); send_bits( state, count - 3, 3 );

        }
        else
        {
            send_code( state, REPZ_11_138, state.ts.bl_tree ); send_bits( state, count - 11, 7 );
        }
        count = 0; prevlen = curlen;
        if(nextlen == 0)
        {
            max_count = 138, min_count = 3;
        }
        else if(curlen == nextlen)
        {
            max_count = 6, min_count = 3;
        }
        else
        {
            max_count = 7, min_count = 4;
        }
    }
}

/* ===========================================================================
* Construct the Huffman tree for the bit lengths and return the index in
* bl_order of the last bit length code to send.
*/
int build_bl_tree( TState &state )
{
    int max_blindex;  /* index of last bit length code of non zero freq */

                      /* Determine the bit length frequencies for literal and distance trees */
    scan_tree( state, (ct_data *)state.ts.dyn_ltree, state.ts.l_desc.max_code );
    scan_tree( state, (ct_data *)state.ts.dyn_dtree, state.ts.d_desc.max_code );

    /* Build the bit length tree: */
    build_tree( state, (tree_desc *)(&state.ts.bl_desc) );
    /* opt_len now includes the length of the tree representations, except
    * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
    */

    /* Determine the number of bit length codes to send. The pkzip format
    * requires that at least 4 bit length codes be sent. (appnote.txt says
    * 3 but the actual value used is 4.)
    */
    for(max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--)
    {
        if(state.ts.bl_tree[bl_order[max_blindex]].dl.len != 0) break;
    }
    /* Update opt_len to include the bit length tree and counts */
    state.ts.opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
    Trace( "\ndyn trees: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len );

    return max_blindex;
}

/* ===========================================================================
* Send the header for a block using dynamic Huffman trees: the counts, the
* lengths of the bit length codes, the literal tree and the distance tree.
* IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
*/
void send_all_trees( TState &state, int lcodes, int dcodes, int blcodes )
{
    int rank;                    /* index in bl_order */

    Assert( state, lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes" );
    Assert( state, lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
        "too many codes" );
    Trace( "\nbl counts: " );
    send_bits( state, lcodes - 257, 5 );
    /* not +255 as stated in appnote.txt 1.93a or -256 in 2.04c */
    send_bits( state, dcodes - 1, 5 );
    send_bits( state, blcodes - 4, 4 ); /* not -3 as stated in appnote.txt */
    for(rank = 0; rank < blcodes; rank++)
    {
        Trace( "\nbl code %2d ", bl_order[rank] );
        send_bits( state, state.ts.bl_tree[bl_order[rank]].dl.len, 3 );
    }
    Trace( "\nbl tree: sent %ld", state.bs.bits_sent );

    send_tree( state, (ct_data *)state.ts.dyn_ltree, lcodes - 1 ); /* send the literal tree */
    Trace( "\nlit tree: sent %ld", state.bs.bits_sent );

    send_tree( state, (ct_data *)state.ts.dyn_dtree, dcodes - 1 ); /* send the distance tree */
    Trace( "\ndist tree: sent %ld", state.bs.bits_sent );
}

/* ===========================================================================
* Determine the best encoding for the current block: dynamic trees, static
* trees or store, and output the encoded block to the zip file. This function
* returns the total compressed length (in bytes) for the file so far.
*/
ulg flush_block( TState &state, char *buf, ulg stored_len, int eof )
{
    ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
    int max_blindex;  /* index of last bit length code of non zero freq */

    state.ts.flag_buf[state.ts.last_flags] = state.ts.flags; /* Save the flags for the last 8 items */

                                                             /* Check if the file is ascii or binary */
    if(*state.ts.file_type == (ush)UNKNOWN) set_file_type( state );

    /* Construct the literal and distance trees */
    build_tree( state, (tree_desc *)(&state.ts.l_desc) );
    Trace( "\nlit data: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len );

    build_tree( state, (tree_desc *)(&state.ts.d_desc) );
    Trace( "\ndist data: dyn %ld, stat %ld", state.ts.opt_len, state.ts.static_len );
    /* At this point, opt_len and static_len are the total bit lengths of
    * the compressed block data, excluding the tree representations.
    */

    /* Build the bit length tree for the above two trees, and get the index
    * in bl_order of the last bit length code to send.
    */
    max_blindex = build_bl_tree( state );

    /* Determine the best encoding. Compute first the block length in bytes */
    opt_lenb = (state.ts.opt_len + 3 + 7) >> 3;
    static_lenb = (state.ts.static_len + 3 + 7) >> 3;
    state.ts.input_len += stored_len; /* for debugging only */

    Trace( "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
        opt_lenb, state.ts.opt_len, static_lenb, state.ts.static_len, stored_len,
        state.ts.last_lit, state.ts.last_dist );

    if(static_lenb <= opt_lenb) opt_lenb = static_lenb;

    // Originally, zip allowed the file to be transformed from a compressed
    // into a stored file in the case where compression failed, there
    // was only one block, and it was allowed to change. I've removed this
    // possibility since the code's cleaner if no changes are allowed.
    //if (stored_len <= opt_lenb && eof && state.ts.cmpr_bytelen == 0L
    //   && state.ts.cmpr_len_bits == 0L && state.seekable)
    //{   // && state.ts.file_method != NULL
    //    // Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there:
    //    Assert(state,buf!=NULL,"block vanished");
    //    copy_block(state,buf, (unsigned)stored_len, 0); // without header
    //    state.ts.cmpr_bytelen = stored_len;
    //    Assert(state,false,"unimplemented *state.ts.file_method = STORE;");
    //    //*state.ts.file_method = STORE;
    //}
    //else
    if(stored_len + 4 <= opt_lenb && buf != (char*)NULL)
    {
        /* 4: two words for the lengths */
        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
        * Otherwise we can't have processed more than WSIZE input bytes since
        * the last block flush, because compression would have been
        * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
        * transform a block into a stored block.
        */
        send_bits( state, (STORED_BLOCK << 1) + eof, 3 );  /* send block type */
        state.ts.cmpr_bytelen += ((state.ts.cmpr_len_bits + 3 + 7) >> 3) + stored_len + 4;
        state.ts.cmpr_len_bits = 0L;

        copy_block( state, buf, (unsigned)stored_len, 1 ); /* with header */
    }
    else if(static_lenb == opt_lenb)
    {
        send_bits( state, (STATIC_TREES << 1) + eof, 3 );
        compress_block( state, (ct_data *)state.ts.static_ltree, (ct_data *)state.ts.static_dtree );
        state.ts.cmpr_len_bits += 3 + state.ts.static_len;
        state.ts.cmpr_bytelen += state.ts.cmpr_len_bits >> 3;
        state.ts.cmpr_len_bits &= 7L;
    }
    else
    {
        send_bits( state, (DYN_TREES << 1) + eof, 3 );
        send_all_trees( state, state.ts.l_desc.max_code + 1, state.ts.d_desc.max_code + 1, max_blindex + 1 );
        compress_block( state, (ct_data *)state.ts.dyn_ltree, (ct_data *)state.ts.dyn_dtree );
        state.ts.cmpr_len_bits += 3 + state.ts.opt_len;
        state.ts.cmpr_bytelen += state.ts.cmpr_len_bits >> 3;
        state.ts.cmpr_len_bits &= 7L;
    }
    Assert( state, ((state.ts.cmpr_bytelen << 3) + state.ts.cmpr_len_bits) == state.bs.bits_sent, "bad compressed size" );
    init_block( state );

    if(eof)
    {
        // Assert(state,input_len == isize, "bad input size");
        bi_windup( state );
        state.ts.cmpr_len_bits += 7;  /* align on byte boundary */
    }
    Trace( "\n" );

    return state.ts.cmpr_bytelen + (state.ts.cmpr_len_bits >> 3);
}

/* ===========================================================================
* Save the match info and tally the frequency counts. Return true if
* the current block must be flushed.
*/
int ct_tally( TState &state, int dist, int lc )
{
    state.ts.l_buf[state.ts.last_lit++] = (uch)lc;
    if(dist == 0)
    {
        /* lc is the unmatched char */
        state.ts.dyn_ltree[lc].fc.freq++;
    }
    else
    {
        /* Here, lc is the match length - MIN_MATCH */
        dist--;             /* dist = match distance - 1 */
        Assert( state, (ush)dist < (ush)MAX_DIST &&
            (ush)lc <= (ush)(MAX_MATCH - MIN_MATCH) &&
            (ush)d_code( dist ) < (ush)D_CODES, "ct_tally: bad match" );

        state.ts.dyn_ltree[state.ts.length_code[lc] + LITERALS + 1].fc.freq++;
        state.ts.dyn_dtree[d_code( dist )].fc.freq++;

        state.ts.d_buf[state.ts.last_dist++] = (ush)dist;
        state.ts.flags |= state.ts.flag_bit;
    }
    state.ts.flag_bit <<= 1;

    /* Output the flags if they fill a byte: */
    if((state.ts.last_lit & 7) == 0)
    {
        state.ts.flag_buf[state.ts.last_flags++] = state.ts.flags;
        state.ts.flags = 0, state.ts.flag_bit = 1;
    }
    /* Try to guess if it is profitable to stop the current block here */
    if(state.level > 2 && (state.ts.last_lit & 0xfff) == 0)
    {
        /* Compute an upper bound for the compressed length */
        ulg out_length = (ulg)state.ts.last_lit * 8L;
        ulg in_length = (ulg)state.ds.strstart - state.ds.block_start;
        int dcode;
        for(dcode = 0; dcode < D_CODES; dcode++)
        {
            out_length += (ulg)state.ts.dyn_dtree[dcode].fc.freq*(5L + extra_dbits[dcode]);
        }
        out_length >>= 3;
        Trace( "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
            state.ts.last_lit, state.ts.last_dist, in_length, out_length,
            100L - out_length * 100L / in_length );
        if(state.ts.last_dist < state.ts.last_lit / 2 && out_length < in_length / 2) return 1;
    }
    return (state.ts.last_lit == LIT_BUFSIZE - 1 || state.ts.last_dist == DIST_BUFSIZE);
    /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
    * on 16 bit machines and because stored blocks are restricted to
    * 64K-1 bytes.
    */
}

/* ===========================================================================
* Send the block data compressed using the given Huffman trees
*/
void compress_block( TState &state, ct_data *ltree, ct_data *dtree )
{
    unsigned dist;      /* distance of matched string */
    int lc;             /* match length or unmatched char (if dist == 0) */
    unsigned lx = 0;    /* running index in l_buf */
    unsigned dx = 0;    /* running index in d_buf */
    unsigned fx = 0;    /* running index in flag_buf */
    uch flag = 0;       /* current flags */
    unsigned code;      /* the code to send */
    int extra;          /* number of extra bits to send */

    if(state.ts.last_lit != 0) do
    {
        if((lx & 7) == 0) flag = state.ts.flag_buf[fx++];
        lc = state.ts.l_buf[lx++];
        if((flag & 1) == 0)
        {
            send_code( state, lc, ltree ); /* send a literal byte */
        }
        else
        {
            /* Here, lc is the match length - MIN_MATCH */
            code = state.ts.length_code[lc];
            send_code( state, code + LITERALS + 1, ltree ); /* send the length code */
            extra = extra_lbits[code];
            if(extra != 0)
            {
                lc -= state.ts.base_length[code];
                send_bits( state, lc, extra );        /* send the extra length bits */
            }
            dist = state.ts.d_buf[dx++];
            /* Here, dist is the match distance - 1 */
            code = d_code( dist );
            Assert( state, code < D_CODES, "bad d_code" );

            send_code( state, code, dtree );       /* send the distance code */
            extra = extra_dbits[code];
            if(extra != 0)
            {
                dist -= state.ts.base_dist[code];
                send_bits( state, dist, extra );   /* send the extra distance bits */
            }
        } /* literal or match pair ? */
        flag >>= 1;
    }
    while(lx < state.ts.last_lit);

    send_code( state, END_BLOCK, ltree );
}

/* ===========================================================================
* Set the file type to ASCII or BINARY, using a crude approximation:
* binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
* IN assertion: the fields freq of dyn_ltree are set and the total of all
* frequencies does not exceed 64K (to fit in an int on 16 bit machines).
*/
void set_file_type( TState &state )
{
    int n = 0;
    unsigned ascii_freq = 0;
    unsigned bin_freq = 0;
    while(n < 7)        bin_freq += state.ts.dyn_ltree[n++].fc.freq;
    while(n < 128)    ascii_freq += state.ts.dyn_ltree[n++].fc.freq;
    while(n < LITERALS) bin_freq += state.ts.dyn_ltree[n++].fc.freq;
    *state.ts.file_type = (ush)(bin_freq >( ascii_freq >> 2 ) ? BINARY : ASCII);
}


/* ===========================================================================
* Initialize the bit string routines.
*/
void bi_init( TState &state, char *tgt_buf, unsigned tgt_size, int flsh_allowed )
{
    state.bs.out_buf = tgt_buf;
    state.bs.out_size = tgt_size;
    state.bs.out_offset = 0;
    state.bs.flush_flg = flsh_allowed;

    state.bs.bi_buf = 0;
    state.bs.bi_valid = 0;
    state.bs.bits_sent = 0L;
}

/* ===========================================================================
* Send a value on a given number of bits.
* IN assertion: length <= 16 and value fits in length bits.
*/
void send_bits( TState &state, int value, int length )
{
    Assert( state, length > 0 && length <= 15, "invalid length" );
    state.bs.bits_sent += (ulg)length;
    /* If not enough room in bi_buf, use (bi_valid) bits from bi_buf and
    * (Buf_size - bi_valid) bits from value to flush the filled bi_buf,
    * then fill in the rest of (value), leaving (length - (Buf_size-bi_valid))
    * unused bits in bi_buf.
    */
    state.bs.bi_buf |= (value << state.bs.bi_valid);
    state.bs.bi_valid += length;
    if(state.bs.bi_valid > (int)Buf_size)
    {
        PUTSHORT( state, state.bs.bi_buf );
        state.bs.bi_valid -= Buf_size;
        state.bs.bi_buf = (unsigned)value >> (length - state.bs.bi_valid);
    }
}

/* ===========================================================================
* Reverse the first len bits of a code, using straightforward code (a faster
* method would use a table)
* IN assertion: 1 <= len <= 15
*/
unsigned bi_reverse( unsigned code, int len )
{
    register unsigned res = 0;
    do
    {
        res |= code & 1;
        code >>= 1, res <<= 1;
    }
    while(--len > 0);
    return res >> 1;
}

/* ===========================================================================
* Write out any remaining bits in an incomplete byte.
*/
void bi_windup( TState &state )
{
    if(state.bs.bi_valid > 8)
    {
        PUTSHORT( state, state.bs.bi_buf );
    }
    else if(state.bs.bi_valid > 0)
    {
        PUTBYTE( state, state.bs.bi_buf );
    }
    if(state.bs.flush_flg)
    {
        state.flush_outbuf( state.param, state.bs.out_buf, &state.bs.out_offset );
    }
    state.bs.bi_buf = 0;
    state.bs.bi_valid = 0;
    state.bs.bits_sent = (state.bs.bits_sent + 7) & ~7;
}

/* ===========================================================================
* Copy a stored block to the zip file, storing first the length and its
* one's complement if requested.
*/
void copy_block( TState &state, char *block, unsigned len, int header )
{
    bi_windup( state );              /* align on byte boundary */

    if(header)
    {
        PUTSHORT( state, (ush)len );
        PUTSHORT( state, (ush)~len );
        state.bs.bits_sent += 2 * 16;
    }
    if(state.bs.flush_flg)
    {
        state.flush_outbuf( state.param, state.bs.out_buf, &state.bs.out_offset );
        state.bs.out_offset = len;
        state.flush_outbuf( state.param, block, &state.bs.out_offset );
    }
    else if(state.bs.out_offset + len > state.bs.out_size)
    {
        Assert( state, false, "output buffer too small for in-memory compression" );
    }
    else
    {
        memcpy( state.bs.out_buf + state.bs.out_offset, block, len );
        state.bs.out_offset += len;
    }
    state.bs.bits_sent += (ulg)len << 3;
}








/* ===========================================================================
*  Prototypes for functions.
*/

void fill_window( TState &state );
ulg deflate_fast( TState &state );

int  longest_match( TState &state, IPos cur_match );


/* ===========================================================================
* Update a hash value with the given input byte
* IN  assertion: all calls to to UPDATE_HASH are made with consecutive
*    input characters, so that a running hash key can be computed from the
*    previous key instead of complete recalculation each time.
*/
#define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)

/* ===========================================================================
* Insert string s in the dictionary and set match_head to the previous head
* of the hash chain (the most recent string with same hash key). Return
* the previous length of the hash chain.
* IN  assertion: all calls to to INSERT_STRING are made with consecutive
*    input characters and the first MIN_MATCH bytes of s are valid
*    (except for the last MIN_MATCH-1 bytes of the input file).
*/
#define INSERT_STRING(s, match_head) \
   (UPDATE_HASH(state.ds.ins_h, state.ds.window[(s) + (MIN_MATCH-1)]), \
    state.ds.prev[(s) & WMASK] = match_head = state.ds.head[state.ds.ins_h], \
    state.ds.head[state.ds.ins_h] = (s))

/* ===========================================================================
* Initialize the "longest match" routines for a new file
*
* IN assertion: window_size is > 0 if the input file is already read or
*    mmap'ed in the window[] array, 0 otherwise. In the first case,
*    window_size is sufficient to contain the whole input file plus
*    MIN_LOOKAHEAD bytes (to avoid referencing memory beyond the end
*    of window[] when looking for matches towards the end).
*/
void lm_init( TState &state, int pack_level, ush *flags )
{
    register unsigned j;

    Assert( state, pack_level >= 1 && pack_level <= 8, "bad pack level" );

    /* Do not slide the window if the whole input is already in memory
    * (window_size > 0)
    */
    state.ds.sliding = 0;
    if(state.ds.window_size == 0L)
    {
        state.ds.sliding = 1;
        state.ds.window_size = (ulg)2L * WSIZE;
    }

    /* Initialize the hash table (avoiding 64K overflow for 16 bit systems).
    * prev[] will be initialized on the fly.
    */
    state.ds.head[HASH_SIZE - 1] = NIL;
    memset( (char*)state.ds.head, NIL, (unsigned)(HASH_SIZE - 1) * sizeof( *state.ds.head ) );

    /* Set the default configuration parameters:
    */
    state.ds.max_lazy_match = configuration_table[pack_level].max_lazy;
    state.ds.good_match = configuration_table[pack_level].good_length;
    state.ds.nice_match = configuration_table[pack_level].nice_length;
    state.ds.max_chain_length = configuration_table[pack_level].max_chain;
    if(pack_level <= 2)
    {
        *flags |= FAST;
    }
    else if(pack_level >= 8)
    {
        *flags |= SLOW;
    }
    /* ??? reduce max_chain_length for binary files */

    state.ds.strstart = 0;
    state.ds.block_start = 0L;

    j = WSIZE;
    j <<= 1; // Can read 64K in one step
    state.ds.lookahead = state.readfunc( state, (char*)state.ds.window, j );

    if(state.ds.lookahead == 0 || state.ds.lookahead == (unsigned)EOF)
    {
        state.ds.eofile = 1, state.ds.lookahead = 0;
        return;
    }
    state.ds.eofile = 0;
    /* Make sure that we always have enough lookahead. This is important
    * if input comes from a device such as a tty.
    */
    if(state.ds.lookahead < MIN_LOOKAHEAD) fill_window( state );

    state.ds.ins_h = 0;
    for(j = 0; j<MIN_MATCH - 1; j++) UPDATE_HASH( state.ds.ins_h, state.ds.window[j] );
    /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
    * not important since only literal bytes will be emitted.
    */
}


/* ===========================================================================
* Set match_start to the longest match starting at the given string and
* return its length. Matches shorter or equal to prev_length are discarded,
* in which case the result is equal to prev_length and match_start is
* garbage.
* IN assertions: cur_match is the head of the hash chain for the current
*   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
*/
// For 80x86 and 680x0 and ARM, an optimized version is in match.asm or
// match.S. The code is functionally equivalent, so you can use the C version
// if desired. Which I do so desire!
int longest_match( TState &state, IPos cur_match )
{
    unsigned chain_length = state.ds.max_chain_length;   /* max hash chain length */
    register uch *scan = state.ds.window + state.ds.strstart; /* current string */
    register uch *match;                    /* matched string */
    register int len;                           /* length of current match */
    int best_len = state.ds.prev_length;                 /* best match length so far */
    IPos limit = state.ds.strstart > (IPos)MAX_DIST ? state.ds.strstart - (IPos)MAX_DIST : NIL;
    /* Stop when cur_match becomes <= limit. To simplify the code,
    * we prevent matches with the string of window index 0.
    */

    // The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
    // It is easy to get rid of this optimization if necessary.
    Assert( state, HASH_BITS >= 8 && MAX_MATCH == 258, "Code too clever" );



    register uch *strend = state.ds.window + state.ds.strstart + MAX_MATCH;
    register uch scan_end1 = scan[best_len - 1];
    register uch scan_end = scan[best_len];

    /* Do not waste too much time if we already have a good match: */
    if(state.ds.prev_length >= state.ds.good_match)
    {
        chain_length >>= 2;
    }

    Assert( state, state.ds.strstart <= state.ds.window_size - MIN_LOOKAHEAD, "insufficient lookahead" );

    do
    {
        Assert( state, cur_match < state.ds.strstart, "no future" );
        match = state.ds.window + cur_match;

        /* Skip to next match if the match length cannot increase
        * or if the match length is less than 2:
        */
        if(match[best_len] != scan_end ||
            match[best_len - 1] != scan_end1 ||
            *match != *scan ||
            *++match != scan[1])      continue;

        /* The check at best_len-1 can be removed because it will be made
        * again later. (This heuristic is not always a win.)
        * It is not necessary to compare scan[2] and match[2] since they
        * are always equal when the other bytes match, given that
        * the hash keys are equal and that HASH_BITS >= 8.
        */
        scan += 2, match++;

        /* We check for insufficient lookahead only every 8th comparison;
        * the 256th check will be made at strstart+258.
        */
        do
        {
        }
        while(*++scan == *++match && *++scan == *++match &&
            *++scan == *++match && *++scan == *++match &&
            *++scan == *++match && *++scan == *++match &&
            *++scan == *++match && *++scan == *++match &&
            scan < strend);

        Assert( state, scan <= state.ds.window + (unsigned)(state.ds.window_size - 1), "wild scan" );

        len = MAX_MATCH - (int)(strend - scan);
        scan = strend - MAX_MATCH;


        if(len > best_len)
        {
            state.ds.match_start = cur_match;
            best_len = len;
            if(len >= state.ds.nice_match) break;
            scan_end1 = scan[best_len - 1];
            scan_end = scan[best_len];
        }
    }
    while((cur_match = state.ds.prev[cur_match & WMASK]) > limit
        && --chain_length != 0);

    return best_len;
}



#define check_match(state,start, match, length)
// or alternatively...
//void check_match(TState &state,IPos start, IPos match, int length)
//{ // check that the match is indeed a match
//    if (memcmp((char*)state.ds.window + match,
//                (char*)state.ds.window + start, length) != EQUAL) {
//        fprintf(stderr,
//            " start %d, match %d, length %d\n",
//            start, match, length);
//        error("invalid match");
//    }
//    if (state.verbose > 1) {
//        fprintf(stderr,"\\[%d,%d]", start-match, length);
//        do { fprintf(stdout,"%c",state.ds.window[start++]); } while (--length != 0);
//    }
//}

/* ===========================================================================
* Fill the window when the lookahead becomes insufficient.
* Updates strstart and lookahead, and sets eofile if end of input file.
*
* IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
* OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
*    At least one byte has been read, or eofile is set; file reads are
*    performed for at least two bytes (required for the translate_eol option).
*/
void fill_window( TState &state )
{
    register unsigned n, m;
    unsigned more;    /* Amount of free space at the end of the window. */

    do
    {
        more = (unsigned)(state.ds.window_size - (ulg)state.ds.lookahead - (ulg)state.ds.strstart);

        /* If the window is almost full and there is insufficient lookahead,
        * move the upper half to the lower one to make room in the upper half.
        */
        if(more == (unsigned)EOF)
        {
            /* Very unlikely, but possible on 16 bit machine if strstart == 0
            * and lookahead == 1 (input done one byte at time)
            */
            more--;

            /* For MMAP or BIG_MEM, the whole input file is already in memory so
            * we must not perform sliding. We must however call (*read_buf)() in
            * order to compute the crc, update lookahead and possibly set eofile.
            */
        }
        else if(state.ds.strstart >= WSIZE + MAX_DIST && state.ds.sliding)
        {

            /* By the IN assertion, the window is not empty so we can't confuse
            * more == 0 with more == 64K on a 16 bit machine.
            */
            memcpy( (char*)state.ds.window, (char*)state.ds.window + WSIZE, (unsigned)WSIZE );
            state.ds.match_start -= WSIZE;
            state.ds.strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */

            state.ds.block_start -= (long)WSIZE;

            for(n = 0; n < HASH_SIZE; n++)
            {
                m = state.ds.head[n];
                state.ds.head[n] = (Pos)(m >= WSIZE ? m - WSIZE : NIL);
            }
            for(n = 0; n < WSIZE; n++)
            {
                m = state.ds.prev[n];
                state.ds.prev[n] = (Pos)(m >= WSIZE ? m - WSIZE : NIL);
                /* If n is not on any hash chain, prev[n] is garbage but
                * its value will never be used.
                */
            }
            more += WSIZE;
        }
        if(state.ds.eofile) return;

        /* If there was no sliding:
        *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
        *    more == window_size - lookahead - strstart
        * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
        * => more >= window_size - 2*WSIZE + 2
        * In the MMAP or BIG_MEM case (not yet supported in gzip),
        *   window_size == input_size + MIN_LOOKAHEAD  &&
        *   strstart + lookahead <= input_size => more >= MIN_LOOKAHEAD.
        * Otherwise, window_size == 2*WSIZE so more >= 2.
        * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
        */
        Assert( state, more >= 2, "more < 2" );

        n = state.readfunc( state, (char*)state.ds.window + state.ds.strstart + state.ds.lookahead, more );

        if(n == 0 || n == (unsigned)EOF)
        {
            state.ds.eofile = 1;
        }
        else
        {
            state.ds.lookahead += n;
        }
    }
    while(state.ds.lookahead < MIN_LOOKAHEAD && !state.ds.eofile);
}

/* ===========================================================================
* Flush the current block, with given end-of-file flag.
* IN assertion: strstart is set to the end of the current match.
*/
#define FLUSH_BLOCK(state,eof) \
   flush_block(state,state.ds.block_start >= 0L ? (char*)&state.ds.window[(unsigned)state.ds.block_start] : \
                (char*)NULL, (long)state.ds.strstart - state.ds.block_start, (eof))

/* ===========================================================================
* Processes a new input file and return its compressed length. This
* function does not perform lazy evaluation of matches and inserts
* new strings in the dictionary only for unmatched strings or for short
* matches. It is used only for the fast compression options.
*/
ulg deflate_fast( TState &state )
{
    IPos hash_head = NIL;       /* head of the hash chain */
    int flush;                  /* set if current block must be flushed */
    unsigned match_length = 0;  /* length of best match */

    state.ds.prev_length = MIN_MATCH - 1;
    while(state.ds.lookahead != 0)
    {
        /* Insert the string window[strstart .. strstart+2] in the
        * dictionary, and set hash_head to the head of the hash chain:
        */
        if(state.ds.lookahead >= MIN_MATCH)
            INSERT_STRING( state.ds.strstart, hash_head );

        /* Find the longest match, discarding those <= prev_length.
        * At this point we have always match_length < MIN_MATCH
        */
        if(hash_head != NIL && state.ds.strstart - hash_head <= MAX_DIST)
        {
            /* To simplify the code, we prevent matches with the string
            * of window index 0 (in particular we have to avoid a match
            * of the string with itself at the start of the input file).
            */
            /* Do not look for matches beyond the end of the input.
            * This is necessary to make deflate deterministic.
            */
            if((unsigned)state.ds.nice_match > state.ds.lookahead) state.ds.nice_match = (int)state.ds.lookahead;
            match_length = longest_match( state, hash_head );
            /* longest_match() sets match_start */
            if(match_length > state.ds.lookahead) match_length = state.ds.lookahead;
        }
        if(match_length >= MIN_MATCH)
        {
            check_match( state, state.ds.strstart, state.ds.match_start, match_length );

            flush = ct_tally( state, state.ds.strstart - state.ds.match_start, match_length - MIN_MATCH );

            state.ds.lookahead -= match_length;

            /* Insert new strings in the hash table only if the match length
            * is not too large. This saves time but degrades compression.
            */
            if(match_length <= state.ds.max_insert_length
                && state.ds.lookahead >= MIN_MATCH)
            {
                match_length--; /* string at strstart already in hash table */
                do
                {
                    state.ds.strstart++;
                    INSERT_STRING( state.ds.strstart, hash_head );
                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                    * always MIN_MATCH bytes ahead.
                    */
                }
                while(--match_length != 0);
                state.ds.strstart++;
            }
            else
            {
                state.ds.strstart += match_length;
                match_length = 0;
                state.ds.ins_h = state.ds.window[state.ds.strstart];
                UPDATE_HASH( state.ds.ins_h, state.ds.window[state.ds.strstart + 1] );
                Assert( state, MIN_MATCH == 3, "Call UPDATE_HASH() MIN_MATCH-3 more times" );
            }
        }
        else
        {
            /* No match, output a literal byte */
            flush = ct_tally( state, 0, state.ds.window[state.ds.strstart] );
            state.ds.lookahead--;
            state.ds.strstart++;
        }
        if(flush) FLUSH_BLOCK( state, 0 ), state.ds.block_start = state.ds.strstart;

        /* Make sure that we always have enough lookahead, except
        * at the end of the input file. We need MAX_MATCH bytes
        * for the next match, plus MIN_MATCH bytes to insert the
        * string following the next match.
        */
        if(state.ds.lookahead < MIN_LOOKAHEAD) fill_window( state );
    }
    return FLUSH_BLOCK( state, 1 ); /* eof */
}

/* ===========================================================================
* Same as above, but achieves better compression. We use a lazy
* evaluation for matches: a match is finally adopted only if there is
* no better match at the next window position.
*/
ulg deflate( TState &state )
{
    IPos hash_head = NIL;       /* head of hash chain */
    IPos prev_match;            /* previous match */
    int flush;                  /* set if current block must be flushed */
    int match_available = 0;    /* set if previous match exists */
    register unsigned match_length = MIN_MATCH - 1; /* length of best match */

    if(state.level <= 3) return deflate_fast( state ); /* optimized for speed */

                                                       /* Process the input block. */
    while(state.ds.lookahead != 0)
    {
        /* Insert the string window[strstart .. strstart+2] in the
        * dictionary, and set hash_head to the head of the hash chain:
        */
        if(state.ds.lookahead >= MIN_MATCH)
            INSERT_STRING( state.ds.strstart, hash_head );

        /* Find the longest match, discarding those <= prev_length.
        */
        state.ds.prev_length = match_length, prev_match = state.ds.match_start;
        match_length = MIN_MATCH - 1;

        if(hash_head != NIL && state.ds.prev_length < state.ds.max_lazy_match &&
            state.ds.strstart - hash_head <= MAX_DIST)
        {
            /* To simplify the code, we prevent matches with the string
            * of window index 0 (in particular we have to avoid a match
            * of the string with itself at the start of the input file).
            */
            /* Do not look for matches beyond the end of the input.
            * This is necessary to make deflate deterministic.
            */
            if((unsigned)state.ds.nice_match > state.ds.lookahead) state.ds.nice_match = (int)state.ds.lookahead;
            match_length = longest_match( state, hash_head );
            /* longest_match() sets match_start */
            if(match_length > state.ds.lookahead) match_length = state.ds.lookahead;

            /* Ignore a length 3 match if it is too distant: */
            if(match_length == MIN_MATCH && state.ds.strstart - state.ds.match_start > TOO_FAR)
            {
                /* If prev_match is also MIN_MATCH, match_start is garbage
                * but we will ignore the current match anyway.
                */
                match_length = MIN_MATCH - 1;
            }
        }
        /* If there was a match at the previous step and the current
        * match is not better, output the previous match:
        */
        if(state.ds.prev_length >= MIN_MATCH && match_length <= state.ds.prev_length)
        {
            unsigned max_insert = state.ds.strstart + state.ds.lookahead - MIN_MATCH;
            check_match( state, state.ds.strstart - 1, prev_match, state.ds.prev_length );
            flush = ct_tally( state, state.ds.strstart - 1 - prev_match, state.ds.prev_length - MIN_MATCH );

            /* Insert in hash table all strings up to the end of the match.
            * strstart-1 and strstart are already inserted.
            */
            state.ds.lookahead -= state.ds.prev_length - 1;
            state.ds.prev_length -= 2;
            do
            {
                if(++state.ds.strstart <= max_insert)
                {
                    INSERT_STRING( state.ds.strstart, hash_head );
                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                    * always MIN_MATCH bytes ahead.
                    */
                }
            }
            while(--state.ds.prev_length != 0);
            state.ds.strstart++;
            match_available = 0;
            match_length = MIN_MATCH - 1;

            if(flush) FLUSH_BLOCK( state, 0 ), state.ds.block_start = state.ds.strstart;

        }
        else if(match_available)
        {
            /* If there was no match at the previous position, output a
            * single literal. If there was a match but the current match
            * is longer, truncate the previous match to a single literal.
            */
            if(ct_tally( state, 0, state.ds.window[state.ds.strstart - 1] ))
            {
                FLUSH_BLOCK( state, 0 ), state.ds.block_start = state.ds.strstart;
            }
            state.ds.strstart++;
            state.ds.lookahead--;
        }
        else
        {
            /* There is no previous match to compare with, wait for
            * the next step to decide.
            */
            match_available = 1;
            state.ds.strstart++;
            state.ds.lookahead--;
        }
        //        Assert(state,strstart <= isize && lookahead <= isize, "a bit too far");

        /* Make sure that we always have enough lookahead, except
        * at the end of the input file. We need MAX_MATCH bytes
        * for the next match, plus MIN_MATCH bytes to insert the
        * string following the next match.
        */
        if(state.ds.lookahead < MIN_LOOKAHEAD) fill_window( state );
    }
    if(match_available) ct_tally( state, 0, state.ds.window[state.ds.strstart - 1] );

    return FLUSH_BLOCK( state, 1 ); /* eof */
}












int putlocal( struct zlist *z, WRITEFUNC wfunc, void *param )
{ // Write a local header described by *z to file *f.  Return a ZE_ error code.
    PUTLG( LOCSIG, f );
    PUTSH( z->ver, f );
    PUTSH( z->lflg, f );
    PUTSH( z->how, f );
    PUTLG( z->tim, f );
    PUTLG( z->crc, f );
    PUTLG( z->siz, f );
    PUTLG( z->len, f );
    PUTSH( z->nam, f );
    PUTSH( z->ext, f );
    size_t res = (size_t)wfunc( param, z->iname, (unsigned int)z->nam );
    if(res != z->nam) return ZE_TEMP;
    if(z->ext)
    {
        res = (size_t)wfunc( param, z->extra, (unsigned int)z->ext );
        if(res != z->ext) return ZE_TEMP;
    }
    return ZE_OK;
}

int putextended( struct zlist *z, WRITEFUNC wfunc, void *param )
{ // Write an extended local header described by *z to file *f. Returns a ZE_ code
    PUTLG( EXTLOCSIG, f );
    PUTLG( z->crc, f );
    PUTLG( z->siz, f );
    PUTLG( z->len, f );
    return ZE_OK;
}

int putcentral( struct zlist *z, WRITEFUNC wfunc, void *param )
{ // Write a central header entry of *z to file *f. Returns a ZE_ code.
    PUTLG( CENSIG, f );
    PUTSH( z->vem, f );
    PUTSH( z->ver, f );
    PUTSH( z->flg, f );
    PUTSH( z->how, f );
    PUTLG( z->tim, f );
    PUTLG( z->crc, f );
    PUTLG( z->siz, f );
    PUTLG( z->len, f );
    PUTSH( z->nam, f );
    PUTSH( z->cext, f );
    PUTSH( z->com, f );
    PUTSH( z->dsk, f );
    PUTSH( z->att, f );
    PUTLG( z->atx, f );
    PUTLG( z->off, f );
    if((size_t)wfunc( param, z->iname, (unsigned int)z->nam ) != z->nam ||
        (z->cext && (size_t)wfunc( param, z->cextra, (unsigned int)z->cext ) != z->cext) ||
        (z->com && (size_t)wfunc( param, z->comment, (unsigned int)z->com ) != z->com))
        return ZE_TEMP;
    return ZE_OK;
}


int putend( int n, ulg s, ulg c, extent m, char *z, WRITEFUNC wfunc, void *param )
{ // write the end of the central-directory-data to file *f.
    PUTLG( ENDSIG, f );
    PUTSH( 0, f );
    PUTSH( 0, f );
    PUTSH( n, f );
    PUTSH( n, f );
    PUTLG( s, f );
    PUTLG( c, f );
    PUTSH( m, f );
    // Write the comment, if any
    if(m && wfunc( param, z, (unsigned int)m ) != m) return ZE_TEMP;
    return ZE_OK;
}






const ulg crc_table[256] = {
    0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
    0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
    0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
    0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
    0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
    0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
    0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
    0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
    0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
    0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
    0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
    0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
    0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
    0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
    0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
    0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
    0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
    0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
    0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
    0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
    0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
    0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
    0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
    0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
    0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
    0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
    0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
    0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
    0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
    0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
    0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
    0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
    0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
    0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
    0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
    0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
    0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
    0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
    0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
    0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
    0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
    0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
    0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
    0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
    0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
    0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
    0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
    0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
    0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
    0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
    0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
    0x2d02ef8dL
};

#define CRC32(c, b) (crc_table[((int)(c) ^ (b)) & 0xff] ^ ((c) >> 8))
#define DO1(buf)  crc = CRC32(crc, *buf++)
#define DO2(buf)  DO1(buf); DO1(buf)
#define DO4(buf)  DO2(buf); DO2(buf)
#define DO8(buf)  DO4(buf); DO4(buf)

ulg crc32( ulg crc, const uch *buf, extent len )
{
    if(buf == NULL) return 0L;
    crc = crc ^ 0xffffffffL;
    while(len >= 8)
    {
        DO8( buf ); len -= 8;
    }
    if(len) do
    {
        DO1( buf );
    }
    while(--len);
    return crc ^ 0xffffffffL;  // (instead of ~c for 64-bit machines)
}


void update_keys( unsigned long *keys, char c )
{
    keys[0] = CRC32( keys[0], c );
    keys[1] += keys[0] & 0xFF;
    keys[1] = keys[1] * 134775813L + 1;
    keys[2] = CRC32( keys[2], keys[1] >> 24 );
}
char decrypt_byte( unsigned long *keys )
{
    unsigned temp = ((unsigned)keys[2] & 0xffff) | 2;
    return (char)(((temp * (temp ^ 1)) >> 8) & 0xff);
}
char zencode( unsigned long *keys, char c )
{
    int t = decrypt_byte( keys );
    update_keys( keys, c );
    return (char)(t^c);
}







int lustricmp( const TCHAR *sa, const TCHAR *sb )
{
    for(const TCHAR *ca = sa, *cb = sb; ; ca++, cb++)
    {
        int ia = tolower( *ca ), ib = tolower( *cb );
        if(ia == ib && ia == 0) return 0;
        if(ia == ib) continue;
        if(ia<ib) return -1;
        if(ia>ib) return 1;
    }
}


bool HasZipSuffix( const TCHAR *fn )
{
    const TCHAR *ext = fn + _tcslen( fn );
    while(ext>fn && *ext != '.') ext--;
    if(ext == fn && *ext != '.') return false;
    if(lustricmp( ext, _T( ".Z" ) ) == 0) return true;
    if(lustricmp( ext, _T( ".zip" ) ) == 0) return true;
    if(lustricmp( ext, _T( ".zoo" ) ) == 0) return true;
    if(lustricmp( ext, _T( ".arc" ) ) == 0) return true;
    if(lustricmp( ext, _T( ".lzh" ) ) == 0) return true;
    if(lustricmp( ext, _T( ".arj" ) ) == 0) return true;
    if(lustricmp( ext, _T( ".gz" ) ) == 0) return true;
    if(lustricmp( ext, _T( ".tgz" ) ) == 0) return true;
    return false;
}








class TZip
{
public:
    TZip( const char *pwd ) : hfout( 0 ), mustclosehfout( false ), hmapout( 0 ), zfis( 0 ), obuf( 0 ), hfin( 0 ), writ( 0 ), oerr( false ), hasputcen( false ), ooffset( 0 ), encwriting( false ), encbuf( 0 ), password( 0 ), state( 0 )
    {
        if(pwd != 0 && *pwd != 0)
        {
            password = new char[strlen( pwd ) + 1]; strcpy( password, pwd );
        }
    }
    ~TZip()
    {
        if(state != 0) delete state; state = 0; if(encbuf != 0) delete[] encbuf; encbuf = 0; if(password != 0) delete[] password; password = 0;
    }

    // These variables say about the file we're writing into
    // We can write to pipe, file-by-handle, file-by-name, memory-to-memmapfile
    char *password;           // keep a copy of the password
    HANDLE hfout;             // if valid, we'll write here (for files or pipes)
    bool mustclosehfout;      // if true, we are responsible for closing hfout
    HANDLE hmapout;           // otherwise, we'll write here (for memmap)
    unsigned ooffset;         // for hfout, this is where the pointer was initially
    ZRESULT oerr;             // did a write operation give rise to an error?
    unsigned writ;            // how far have we written. This is maintained by Add, not write(), to avoid confusion over seeks
    bool ocanseek;            // can we seek?
    char *obuf;               // this is where we've locked mmap to view.
    unsigned int opos;        // current pos in the mmap
    unsigned int mapsize;     // the size of the map we created
    bool hasputcen;           // have we yet placed the central directory?
    bool encwriting;          // if true, then we'll encrypt stuff using 'keys' before we write it to disk
    unsigned long keys[3];    // keys are initialised inside Add()
    char *encbuf;             // if encrypting, then this is a temporary workspace for encrypting the data
    unsigned int encbufsize;  // (to be used and resized inside write(), and deleted in the destructor)
                              //
    TZipFileInfo *zfis;       // each file gets added onto this list, for writing the table at the end
    TState *state;            // we use just one state object per zip, because it's big (500k)

    ZRESULT Create( void *z, unsigned int len, DWORD flags );
    static unsigned sflush( void *param, const char *buf, unsigned *size );
    static unsigned swrite( void *param, const char *buf, unsigned size );
    unsigned int write( const char *buf, unsigned int size );
    bool oseek( unsigned int pos );
    ZRESULT GetMemory( void **pbuf, unsigned long *plen );
    ZRESULT Close();

    // some variables to do with the file currently being read:
    // I haven't done it object-orientedly here, just put them all
    // together, since OO didn't seem to make the design any clearer.
    ulg attr; iztimes times; ulg timestamp;  // all open_* methods set these
    bool iseekable; long isize, ired;         // size is not set until close() on pips
    ulg crc;                                 // crc is not set until close(). iwrit is cumulative
    HANDLE hfin; bool selfclosehf;           // for input files and pipes
    const char *bufin; unsigned int lenin, posin; // for memory
                                                  // and a variable for what we've done with the input: (i.e. compressed it!)
    ulg csize;                               // compressed size, set by the compression routines
                                             // and this is used by some of the compression routines
    char buf[16384];


    ZRESULT open_file( const TCHAR *fn );
    ZRESULT open_handle( HANDLE hf, unsigned int len );
    ZRESULT open_mem( void *src, unsigned int len );
    ZRESULT open_dir();
    static unsigned sread( TState &s, char *buf, unsigned size );
    unsigned read( char *buf, unsigned size );
    ZRESULT iclose();

    ZRESULT ideflate( TZipFileInfo *zfi );
    ZRESULT istore();

    ZRESULT Add( const TCHAR *odstzn, void *src, unsigned int len, DWORD flags );
    ZRESULT AddCentral();

};



ZRESULT TZip::Create( void *z, unsigned int len, DWORD flags )
{
    if(hfout != 0 || hmapout != 0 || obuf != 0 || writ != 0 || oerr != ZR_OK || hasputcen) return ZR_NOTINITED;
    //
    if(flags == ZIP_HANDLE)
    {
        HANDLE hf = (HANDLE)z;
        hfout = hf; mustclosehfout = false;
#ifdef DuplicateHandle
        BOOL res = DuplicateHandle( GetCurrentProcess(), hf, GetCurrentProcess(), &hfout, 0, FALSE, DUPLICATE_SAME_ACCESS );
        if(res) mustclosehandle = true;
#endif
        // now we have hfout. Either we duplicated the handle and we close it ourselves
        // (while the caller closes h themselves), or we couldn't duplicate it.
        DWORD res = GetFilePosZ( hfout );
        ocanseek = (res != 0xFFFFFFFF);
        ooffset = ocanseek ? res : 0;
        return ZR_OK;
    }
    else if(flags == ZIP_FILENAME)
    {
        const TCHAR *fn = (const TCHAR*)z;
#ifdef ZIP_STD
        hfout = fopen( fn, "wb" );
        if(hfout == 0) return ZR_NOFILE;
#else
        hfout = CreateFile( fn, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL );
        if(hfout == INVALID_HANDLE_VALUE)
        {
            hfout = 0; return ZR_NOFILE;
        }
#endif
        ocanseek = true;
        ooffset = 0;
        mustclosehfout = true;
        return ZR_OK;
    }
    else if(flags == ZIP_MEMORY)
    {
        unsigned int size = len;
        if(size == 0) return ZR_MEMSIZE;
#ifdef ZIP_STD
        if(z != 0) obuf = (char*)z;
        else return ZR_ARGS;
#else
        if(z != 0) obuf = (char*)z;
        else
        {
            hmapout = CreateFileMapping( INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, size, NULL );
            if(hmapout == NULL) return ZR_NOALLOC;
            obuf = (char*)MapViewOfFile( hmapout, FILE_MAP_ALL_ACCESS, 0, 0, size );
            if(obuf == 0)
            {
                CloseHandle( hmapout ); hmapout = 0; return ZR_NOALLOC;
            }
        }
#endif
        ocanseek = true;
        opos = 0; mapsize = size;
        return ZR_OK;
    }
    else return ZR_ARGS;
}

unsigned TZip::sflush( void *param, const char *buf, unsigned *size )
{ // static
    if(*size == 0) return 0;
    TZip *zip = (TZip*)param;
    unsigned int writ = zip->write( buf, *size );
    if(writ != 0) *size = 0;
    return writ;
}
unsigned TZip::swrite( void *param, const char *buf, unsigned size )
{ // static
    if(size == 0) return 0;
    TZip *zip = (TZip*)param; return zip->write( buf, size );
}
unsigned int TZip::write( const char *buf, unsigned int size )
{
    const char *srcbuf = buf;
    if(encwriting)
    {
        if(encbuf != 0 && encbufsize<size)
        {
            delete[] encbuf; encbuf = 0;
        }
        if(encbuf == 0)
        {
            encbuf = new char[size * 2]; encbufsize = size;
        }
        memcpy( encbuf, buf, size );
        for(unsigned int i = 0; i<size; i++) encbuf[i] = zencode( keys, encbuf[i] );
        srcbuf = encbuf;
    }
    if(obuf != 0)
    {
        if(opos + size >= mapsize)
        {
            oerr = ZR_MEMSIZE; return 0;
        }
        memcpy( obuf + opos, srcbuf, size );
        opos += size;
        return size;
    }
    else if(hfout != 0)
    {
#ifdef ZIP_STD
        DWORD writ = (DWORD)fwrite( srcbuf, 1, size, hfout );
#else
        DWORD writ; WriteFile( hfout, srcbuf, size, &writ, NULL );
#endif
        return writ;
    }
    oerr = ZR_NOTINITED; return 0;
}

bool TZip::oseek( unsigned int pos )
{
    if(!ocanseek)
    {
        oerr = ZR_SEEK; return false;
    }
    if(obuf != 0)
    {
        if(pos >= mapsize)
        {
            oerr = ZR_MEMSIZE; return false;
        }
        opos = pos;
        return true;
    }
    else if(hfout != 0)
    {
#ifdef ZIP_STD
        fseek( hfout, pos + ooffset, SEEK_SET );
#else
        SetFilePointer( hfout, pos + ooffset, NULL, FILE_BEGIN );
#endif
        return true;
    }
    oerr = ZR_NOTINITED; return 0;
}

ZRESULT TZip::GetMemory( void **pbuf, unsigned long *plen )
{ // When the user calls GetMemory, they're presumably at the end
  // of all their adding. In any case, we have to add the central
  // directory now, otherwise the memory we tell them won't be complete.
    if(!hasputcen) AddCentral(); hasputcen = true;
    if(pbuf != NULL) *pbuf = (void*)obuf;
    if(plen != NULL) *plen = writ;
    if(obuf == NULL) return ZR_NOTMMAP;
    return ZR_OK;
}

ZRESULT TZip::Close()
{ // if the directory hadn't already been added through a call to GetMemory,
  // then we do it now
    ZRESULT res = ZR_OK; if(!hasputcen) res = AddCentral(); hasputcen = true;
#ifdef ZIP_STD
    if(hfout != 0 && mustclosehfout) fclose( hfout ); hfout = 0; mustclosehfout = false;
#else
    if(obuf != 0 && hmapout != 0) UnmapViewOfFile( obuf ); obuf = 0;
    if(hmapout != 0) CloseHandle( hmapout ); hmapout = 0;
    if(hfout != 0 && mustclosehfout) CloseHandle( hfout ); hfout = 0; mustclosehfout = false;
#endif
    return res;
}




ZRESULT TZip::open_file( const TCHAR *fn )
{
    hfin = 0; bufin = 0; selfclosehf = false; crc = CRCVAL_INITIAL; isize = 0; csize = 0; ired = 0;
    if(fn == 0) return ZR_ARGS;
#ifdef ZIP_STD
    HANDLE hf = fopen( fn, "rb" );
    if(hf == 0) return ZR_NOFILE;
    ZRESULT res = open_handle( hf, 0 );
    if(res != ZR_OK)
    {
        fclose( hf ); return res;
    }
#else
    HANDLE hf = CreateFile( fn, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL );
    if(hf == INVALID_HANDLE_VALUE) return ZR_NOFILE;
    ZRESULT res = open_handle( hf, 0 );
    if(res != ZR_OK)
    {
        CloseHandle( hf ); return res;
    }
#endif
    selfclosehf = true;
    return ZR_OK;
}
ZRESULT TZip::open_handle( HANDLE hf, unsigned int len )
{
    hfin = 0; bufin = 0; selfclosehf = false; crc = CRCVAL_INITIAL; isize = 0; csize = 0; ired = 0;
    if(hf == 0 || hf == INVALID_HANDLE_VALUE) return ZR_ARGS;
    bool canseek;
#ifdef ZIP_STD
    struct stat st; fstat( fileno( hf ), &st ); canseek = S_ISREG( st.st_mode );
#else
    DWORD res = SetFilePointer( hfout, 0, 0, FILE_CURRENT );
    canseek = (res != 0xFFFFFFFF);
#endif
    if(canseek)
    {
        ZRESULT res = GetFileInfo( hf, &attr, &isize, &times, &timestamp );
        if(res != ZR_OK) return res;
#ifdef ZIP_STD
        fseek( hf, 0, SEEK_SET );
#else
        SetFilePointer( hf, 0, NULL, FILE_BEGIN ); // because GetFileInfo will have screwed it up
#endif
        iseekable = true; hfin = hf;
        return ZR_OK;
    }
    else
    {
        attr = 0x80000000;      // just a normal file
        isize = -1;            // can't know size until at the end
        if(len != 0) isize = len; // unless we were told explicitly!
        iseekable = false;
        WORD dosdate, dostime; GetNow( &times.atime, &dosdate, &dostime );
        times.mtime = times.atime;
        times.ctime = times.atime;
        timestamp = (WORD)dostime | (((DWORD)dosdate) << 16);
        hfin = hf;
        return ZR_OK;
    }
}
ZRESULT TZip::open_mem( void *src, unsigned int len )
{
    hfin = 0; bufin = (const char*)src; selfclosehf = false; crc = CRCVAL_INITIAL; ired = 0; csize = 0; ired = 0;
    lenin = len; posin = 0;
    if(src == 0 || len == 0) return ZR_ARGS;
    attr = 0x80000000; // just a normal file
    isize = len;
    iseekable = true;
    WORD dosdate, dostime; GetNow( &times.atime, &dosdate, &dostime );
    times.mtime = times.atime;
    times.ctime = times.atime;
    timestamp = (WORD)dostime | (((DWORD)dosdate) << 16);
    return ZR_OK;
}
ZRESULT TZip::open_dir()
{
    hfin = 0; bufin = 0; selfclosehf = false; crc = CRCVAL_INITIAL; isize = 0; csize = 0; ired = 0;
    attr = 0x41C00010; // a readable writable directory, and again directory
    isize = 0;
    iseekable = false;
    WORD dosdate, dostime; GetNow( &times.atime, &dosdate, &dostime );
    times.mtime = times.atime;
    times.ctime = times.atime;
    timestamp = (WORD)dostime | (((DWORD)dosdate) << 16);
    return ZR_OK;
}

unsigned TZip::sread( TState &s, char *buf, unsigned size )
{ // static
    TZip *zip = (TZip*)s.param;
    return zip->read( buf, size );
}

unsigned TZip::read( char *buf, unsigned size )
{
    if(bufin != 0)
    {
        if(posin >= lenin) return 0; // end of input
        ulg red = lenin - posin;
        if(red>size) red = size;
        memcpy( buf, bufin + posin, red );
        posin += red;
        ired += red;
        crc = crc32( crc, (uch*)buf, red );
        return red;
    }
    else if(hfin != 0)
    {
        DWORD red;
#ifdef ZIP_STD
        red = (DWORD)fread( buf, 1, size, hfin );
        if(red == 0) return 0;
#else
        BOOL ok = ReadFile( hfin, buf, size, &red, NULL );
        if(!ok) return 0;
#endif
        ired += red;
        crc = crc32( crc, (uch*)buf, red );
        return red;
    }
    else
    {
        oerr = ZR_NOTINITED; return 0;
    }
}

ZRESULT TZip::iclose()
{
#ifdef ZIP_STD
    if(selfclosehf && hfin != 0) fclose( hfin ); hfin = 0;
#else
    if(selfclosehf && hfin != 0) CloseHandle( hfin ); hfin = 0;
#endif
    bool mismatch = (isize != -1 && isize != ired);
    isize = ired; // and crc has been being updated anyway
    if(mismatch) return ZR_MISSIZE;
    else return ZR_OK;
}



ZRESULT TZip::ideflate( TZipFileInfo *zfi )
{
    if(state == 0) state = new TState();
    // It's a very big object! 500k! We allocate it on the heap, because PocketPC's
    // stack breaks if we try to put it all on the stack. It will be deleted lazily
    state->err = 0;
    state->readfunc = sread; state->flush_outbuf = sflush;
    state->param = this; state->level = 8; state->seekable = iseekable; state->err = NULL;
    // the following line will make ct_init realise it has to perform the init
    state->ts.static_dtree[0].dl.len = 0;
    // Thanks to Alvin77 for this crucial fix:
    state->ds.window_size = 0;
    //  I think that covers everything that needs to be initted.
    //
    bi_init( *state, buf, sizeof( buf ), 1 ); // it used to be just 1024-size, not 16384 as here
    ct_init( *state, &zfi->att );
    lm_init( *state, state->level, &zfi->flg );
    ulg sz = deflate( *state );
    csize = sz;
    ZRESULT r = ZR_OK; if(state->err != NULL) r = ZR_FLATE;
    return r;
}

ZRESULT TZip::istore()
{
    ulg size = 0;
    for(;;)
    {
        unsigned int cin = read( buf, 16384 ); if(cin <= 0 || cin == (unsigned int)EOF) break;
        unsigned int cout = write( buf, cin ); if(cout != cin) return ZR_MISSIZE;
        size += cin;
    }
    csize = size;
    return ZR_OK;
}





bool has_seeded = false;
ZRESULT TZip::Add( const TCHAR *odstzn, void *src, unsigned int len, DWORD flags )
{
    if(oerr) return ZR_FAILED;
    if(hasputcen) return ZR_ENDED;

    // if we use password encryption, then every isize and csize is 12 bytes bigger
    int passex = 0; if(password != 0 && flags != ZIP_FOLDER) passex = 12;

    // zip has its own notion of what its names should look like: i.e. dir/file.stuff
    TCHAR dstzn[MAX_PATH]; _tcsncpy( dstzn, odstzn, MAX_PATH ); dstzn[MAX_PATH - 1] = 0;
    if(*dstzn == 0) return ZR_ARGS;
    TCHAR *d = dstzn; while(*d != 0)
    {
        if(*d == '\\') *d = '/'; d++;
    }
    bool isdir = (flags == ZIP_FOLDER);
    bool needs_trailing_slash = (isdir && dstzn[_tcslen( dstzn ) - 1] != '/');
    int method = DEFLATE; if(isdir || HasZipSuffix( dstzn )) method = STORE;

    // now open whatever was our input source:
    ZRESULT openres;
    if(flags == ZIP_FILENAME) openres = open_file( (const TCHAR*)src );
    else if(flags == ZIP_HANDLE) openres = open_handle( (HANDLE)src, len );
    else if(flags == ZIP_MEMORY) openres = open_mem( src, len );
    else if(flags == ZIP_FOLDER) openres = open_dir();
    else return ZR_ARGS;
    if(openres != ZR_OK) return openres;

    // A zip "entry" consists of a local header (which includes the file name),
    // then the compressed data, and possibly an extended local header.

    // Initialize the local header
    TZipFileInfo zfi; zfi.nxt = NULL;
    strcpy( zfi.name, "" );
#ifdef UNICODE
    WideCharToMultiByte( CP_UTF8, 0, dstzn, -1, zfi.iname, MAX_PATH, 0, 0 );
#else
    strncpy( zfi.iname, dstzn, MAX_PATH ); zfi.iname[MAX_PATH - 1] = 0;
#endif
    zfi.nam = strlen( zfi.iname );
    if(needs_trailing_slash)
    {
        strcat( zfi.iname, "/" ); zfi.nam++;
    }
    strcpy( zfi.zname, "" );
    zfi.extra = NULL; zfi.ext = 0;   // extra header to go after this compressed data, and its length
    zfi.cextra = NULL; zfi.cext = 0; // extra header to go in the central end-of-zip directory, and its length
    zfi.comment = NULL; zfi.com = 0; // comment, and its length
    zfi.mark = 1;
    zfi.dosflag = 0;
    zfi.att = (ush)BINARY;
    zfi.vem = (ush)0xB17; // 0xB00 is win32 os-code. 0x17 is 23 in decimal: zip 2.3
    zfi.ver = (ush)20;    // Needs PKUNZIP 2.0 to unzip it
    zfi.tim = timestamp;
    // Even though we write the header now, it will have to be rewritten, since we don't know compressed size or crc.
    zfi.crc = 0;            // to be updated later
    zfi.flg = 8;            // 8 means 'there is an extra header'. Assume for the moment that we need it.
    if(password != 0 && !isdir) zfi.flg = 9;  // and 1 means 'password-encrypted'
    zfi.lflg = zfi.flg;     // to be updated later
    zfi.how = (ush)method;  // to be updated later
    zfi.siz = (ulg)(method == STORE && isize >= 0 ? isize + passex : 0); // to be updated later
    zfi.len = (ulg)(isize);  // to be updated later
    zfi.dsk = 0;
    zfi.atx = attr;
    zfi.off = writ + ooffset;         // offset within file of the start of this local record
                                      // stuff the 'times' structure into zfi.extra

                                      // nb. apparently there's a problem with PocketPC CE(zip)->CE(unzip) fails. And removing the following block fixes it up.
    char xloc[EB_L_UT_SIZE]; zfi.extra = xloc;  zfi.ext = EB_L_UT_SIZE;
    char xcen[EB_C_UT_SIZE]; zfi.cextra = xcen; zfi.cext = EB_C_UT_SIZE;
    xloc[0] = 'U';
    xloc[1] = 'T';
    xloc[2] = EB_UT_LEN( 3 );       // length of data part of e.f.
    xloc[3] = 0;
    xloc[4] = EB_UT_FL_MTIME | EB_UT_FL_ATIME | EB_UT_FL_CTIME;
    xloc[5] = (char)(times.mtime);
    xloc[6] = (char)(times.mtime >> 8);
    xloc[7] = (char)(times.mtime >> 16);
    xloc[8] = (char)(times.mtime >> 24);
    xloc[9] = (char)(times.atime);
    xloc[10] = (char)(times.atime >> 8);
    xloc[11] = (char)(times.atime >> 16);
    xloc[12] = (char)(times.atime >> 24);
    xloc[13] = (char)(times.ctime);
    xloc[14] = (char)(times.ctime >> 8);
    xloc[15] = (char)(times.ctime >> 16);
    xloc[16] = (char)(times.ctime >> 24);
    memcpy( zfi.cextra, zfi.extra, EB_C_UT_SIZE );
    zfi.cextra[EB_LEN] = EB_UT_LEN( 1 );


    // (1) Start by writing the local header:
    int r = putlocal( &zfi, swrite, this );
    if(r != ZE_OK)
    {
        iclose(); return ZR_WRITE;
    }
    writ += 4 + LOCHEAD + (unsigned int)zfi.nam + (unsigned int)zfi.ext;
    if(oerr != ZR_OK)
    {
        iclose(); return oerr;
    }

    // (1.5) if necessary, write the encryption header
    keys[0] = 305419896L;
    keys[1] = 591751049L;
    keys[2] = 878082192L;
    for(const char *cp = password; cp != 0 && *cp != 0; cp++) update_keys( keys, *cp );
    // generate some random bytes
#ifdef ZIP_STD
    if(!has_seeded) srand( (unsigned)time( 0 ) );
#else
    if(!has_seeded) srand( GetTickCount() ^ (unsigned long)GetDesktopWindow() );
#endif
    char encbuf[12]; for(int i = 0; i<12; i++) encbuf[i] = (char)((rand() >> 7) & 0xff);
    encbuf[11] = (char)((zfi.tim >> 8) & 0xff);
    for(int ei = 0; ei<12; ei++) encbuf[ei] = zencode( keys, encbuf[ei] );
    if(password != 0 && !isdir)
    {
        swrite( this, encbuf, 12 ); writ += 12;
    }

    //(2) Write deflated/stored file to zip file
    ZRESULT writeres = ZR_OK;
    encwriting = (password != 0 && !isdir);  // an object member variable to say whether we write to disk encrypted
    if(!isdir && method == DEFLATE) writeres = ideflate( &zfi );
    else if(!isdir && method == STORE) writeres = istore();
    else if(isdir) csize = 0;
    encwriting = false;
    iclose();
    writ += csize;
    if(oerr != ZR_OK) return oerr;
    if(writeres != ZR_OK) return ZR_WRITE;

    // (3) Either rewrite the local header with correct information...
    bool first_header_has_size_right = (zfi.siz == csize + passex);
    zfi.crc = crc;
    zfi.siz = csize + passex;
    zfi.len = isize;
    if(ocanseek && (password == 0 || isdir))
    {
        zfi.how = (ush)method;
        if((zfi.flg & 1) == 0) zfi.flg &= ~8; // clear the extended local header flag
        zfi.lflg = zfi.flg;
        // rewrite the local header:
        if(!oseek( zfi.off - ooffset )) return ZR_SEEK;
        if((r = putlocal( &zfi, swrite, this )) != ZE_OK) return ZR_WRITE;
        if(!oseek( writ )) return ZR_SEEK;
    }
    else
    { // (4) ... or put an updated header at the end
        if(zfi.how != (ush)method) return ZR_NOCHANGE;
        if(method == STORE && !first_header_has_size_right) return ZR_NOCHANGE;
        if((r = putextended( &zfi, swrite, this )) != ZE_OK) return ZR_WRITE;
        writ += 16L;
        zfi.flg = zfi.lflg; // if flg modified by inflate, for the central index
    }
    if(oerr != ZR_OK) return oerr;

    // Keep a copy of the zipfileinfo, for our end-of-zip directory
    char *cextra = new char[zfi.cext]; memcpy( cextra, zfi.cextra, zfi.cext ); zfi.cextra = cextra;
    TZipFileInfo *pzfi = new TZipFileInfo; memcpy( pzfi, &zfi, sizeof( zfi ) );
    if(zfis == NULL) zfis = pzfi;
    else
    {
        TZipFileInfo *z = zfis; while(z->nxt != NULL) z = z->nxt; z->nxt = pzfi;
    }
    return ZR_OK;
}

ZRESULT TZip::AddCentral()
{ // write central directory
    int numentries = 0;
    ulg pos_at_start_of_central = writ;
    //ulg tot_unc_size=0, tot_compressed_size=0;
    bool okay = true;
    for(TZipFileInfo *zfi = zfis; zfi != NULL; )
    {
        if(okay)
        {
            int res = putcentral( zfi, swrite, this );
            if(res != ZE_OK) okay = false;
        }
        writ += 4 + CENHEAD + (unsigned int)zfi->nam + (unsigned int)zfi->cext + (unsigned int)zfi->com;
        //tot_unc_size += zfi->len;
        //tot_compressed_size += zfi->siz;
        numentries++;
        //
        TZipFileInfo *zfinext = zfi->nxt;
        if(zfi->cextra != 0) delete[] zfi->cextra;
        delete zfi;
        zfi = zfinext;
    }
    ulg center_size = writ - pos_at_start_of_central;
    if(okay)
    {
        int res = putend( numentries, center_size, pos_at_start_of_central + ooffset, 0, NULL, swrite, this );
        if(res != ZE_OK) okay = false;
        writ += 4 + ENDHEAD + 0;
    }
    if(!okay) return ZR_WRITE;
    return ZR_OK;
}





ZRESULT lasterrorZ = ZR_OK;

unsigned int FormatZipMessageZ( ZRESULT code, char *buf, unsigned int len )
{
    if(code == ZR_RECENT) code = lasterrorZ;
    const char *msg = "unknown zip result code";
    switch(code)
    {
        case ZR_OK: msg = "Success"; break;
        case ZR_NODUPH: msg = "Culdn't duplicate handle"; break;
        case ZR_NOFILE: msg = "Couldn't create/open file"; break;
        case ZR_NOALLOC: msg = "Failed to allocate memory"; break;
        case ZR_WRITE: msg = "Error writing to file"; break;
        case ZR_NOTFOUND: msg = "File not found in the zipfile"; break;
        case ZR_MORE: msg = "Still more data to unzip"; break;
        case ZR_CORRUPT: msg = "Zipfile is corrupt or not a zipfile"; break;
        case ZR_READ: msg = "Error reading file"; break;
        case ZR_ARGS: msg = "Caller: faulty arguments"; break;
        case ZR_PARTIALUNZ: msg = "Caller: the file had already been partially unzipped"; break;
        case ZR_NOTMMAP: msg = "Caller: can only get memory of a memory zipfile"; break;
        case ZR_MEMSIZE: msg = "Caller: not enough space allocated for memory zipfile"; break;
        case ZR_FAILED: msg = "Caller: there was a previous error"; break;
        case ZR_ENDED: msg = "Caller: additions to the zip have already been ended"; break;
        case ZR_ZMODE: msg = "Caller: mixing creation and opening of zip"; break;
        case ZR_NOTINITED: msg = "Zip-bug: internal initialisation not completed"; break;
        case ZR_SEEK: msg = "Zip-bug: trying to seek the unseekable"; break;
        case ZR_MISSIZE: msg = "Zip-bug: the anticipated size turned out wrong"; break;
        case ZR_NOCHANGE: msg = "Zip-bug: tried to change mind, but not allowed"; break;
        case ZR_FLATE: msg = "Zip-bug: an internal error during flation"; break;
    }
    unsigned int mlen = (unsigned int)strlen( msg );
    if(buf == 0 || len == 0) return mlen;
    unsigned int n = mlen; if(n + 1>len) n = len - 1;
    strncpy( buf, msg, n ); buf[n] = 0;
    return mlen;
}



typedef struct
{
    DWORD flag;
    TZip *zip;
} TZipHandleData;


HZIP CreateZipInternal( void *z, unsigned int len, DWORD flags, const char *password )
{
    TZip *zip = new TZip( password );
    lasterrorZ = zip->Create( z, len, flags );
    if(lasterrorZ != ZR_OK)
    {
        delete zip; return 0;
    }
    TZipHandleData *han = new TZipHandleData;
    han->flag = 2; han->zip = zip; return (HZIP)han;
}
HZIP CreateZipHandle( HANDLE h, const char *password )
{
    return CreateZipInternal( h, 0, ZIP_HANDLE, password );
}
HZIP CreateZip( const TCHAR *fn, const char *password )
{
    return CreateZipInternal( (void*)fn, 0, ZIP_FILENAME, password );
}
HZIP CreateZip( void *z, unsigned int len, const char *password )
{
    return CreateZipInternal( z, len, ZIP_MEMORY, password );
}


ZRESULT ZipAddInternal( HZIP hz, const TCHAR *dstzn, void *src, unsigned int len, DWORD flags )
{
    if(hz == 0)
    {
        lasterrorZ = ZR_ARGS; return ZR_ARGS;
    }
    TZipHandleData *han = (TZipHandleData*)hz;
    if(han->flag != 2)
    {
        lasterrorZ = ZR_ZMODE; return ZR_ZMODE;
    }
    TZip *zip = han->zip;
    lasterrorZ = zip->Add( dstzn, src, len, flags );
    return lasterrorZ;
}
ZRESULT ZipAdd( HZIP hz, const TCHAR *dstzn, const TCHAR *fn )
{
    return ZipAddInternal( hz, dstzn, (void*)fn, 0, ZIP_FILENAME );
}
ZRESULT ZipAdd( HZIP hz, const TCHAR *dstzn, void *src, unsigned int len )
{
    return ZipAddInternal( hz, dstzn, src, len, ZIP_MEMORY );
}
ZRESULT ZipAddHandle( HZIP hz, const TCHAR *dstzn, HANDLE h )
{
    return ZipAddInternal( hz, dstzn, h, 0, ZIP_HANDLE );
}
ZRESULT ZipAddHandle( HZIP hz, const TCHAR *dstzn, HANDLE h, unsigned int len )
{
    return ZipAddInternal( hz, dstzn, h, len, ZIP_HANDLE );
}
ZRESULT ZipAddFolder( HZIP hz, const TCHAR *dstzn )
{
    return ZipAddInternal( hz, dstzn, 0, 0, ZIP_FOLDER );
}



ZRESULT ZipGetMemory( HZIP hz, void **buf, unsigned long *len )
{
    if(hz == 0)
    {
        if(buf != 0) *buf = 0; if(len != 0) *len = 0; lasterrorZ = ZR_ARGS; return ZR_ARGS;
    }
    TZipHandleData *han = (TZipHandleData*)hz;
    if(han->flag != 2)
    {
        lasterrorZ = ZR_ZMODE; return ZR_ZMODE;
    }
    TZip *zip = han->zip;
    lasterrorZ = zip->GetMemory( buf, len );
    return lasterrorZ;
}

ZRESULT CloseZipZ( HZIP hz )
{
    if(hz == 0)
    {
        lasterrorZ = ZR_ARGS; return ZR_ARGS;
    }
    TZipHandleData *han = (TZipHandleData*)hz;
    if(han->flag != 2)
    {
        lasterrorZ = ZR_ZMODE; return ZR_ZMODE;
    }
    TZip *zip = han->zip;
    lasterrorZ = zip->Close();
    delete zip;
    delete han;
    return lasterrorZ;
}

bool IsZipHandleZ( HZIP hz )
{
    if(hz == 0) return false;
    TZipHandleData *han = (TZipHandleData*)hz;
    return (han->flag == 2);
}

